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Guide to Informix Enterprise Replication, Version 9.2

1. Follows naming conventions on your operating system Identifiers p 8 8 Follows naming conventions on your operating system Identifiers p 8 8 Integer TE HANK Command Line Utility 11 35 cdr define server 11 36 Guide to Informix Enterprise Replication table Options Long Form Short Form ats A idle i recv r ris R send S Examples into directory cdr ats cdr define server recv dbspace2 The options for cdr define server have the meanings shown in the following Meaning Activates aborted transaction spooling for replicate transactions that fail to be applied to the target database For more information see Chapter 10 Causes an inactive connection to be terminated after timeout minutes If timeout is 0 the connection does not timeout The default value is 0 Assigns the receive queue to the dbspace recv_space If this option is omitted the receive queue is in the root dbspace Activates row information spooling for replicate row data that fails conflict resolution or encounters repli cation order problems For more information see Chapter 10 Assigns the send queue to the dbspace send_space If this option is omitted the receive queue is in the root dbspace The following example connects to the database server stan initializes Enter prise Replication and sets the idle time out of 500 minutes The example also specifies that the send queue should be stored i
2. The preceding two lines cause replicated data to immediately stop flowing to s3 from s1 s2 s4 and s5 The corresponding command in the CLU is cdr suspend serv c sl g_s3 g_sl g_s2 g_s4 g_s5 API Functions 12 47 Appendixes Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Configuration Parameters SMI Tables for Enterprise Replication Return Codes Fine Tuning Enterprise Replication SQLHOSTS Registry Key Enterprise Replication onstat g Options a z dh Configuration Parameters The database server configuration file ONCONFIG includes the following configuration parameters that affect the behavior of Enterprise Replication CDR_DSLOCKWAIT CDR_EVALTHREADS CDR_LOGDELTA CDR_NIFCOMPRESS CDR_NIFRETRY CDR_QUEUEMEM If you use both DBSERVERNAME and DBSERVERALIASES DBSERVERNAME should refer to the network connection and not to ashared memory connection For information about database server aliases refer to the Administrator s Guide for Informix Dynamic Server 2000 CDR_DSLOCKWAIT CDR_DSLOCKWAIT value 5 units seconds takes effect when shared memory is initialized The CDR_DSLOCKWAIT configuration parameter specifies the number of seconds the data synchronization component waits for database locks to be released The CDR_DSLOCKWAIT parameter behaves similarly to the SET LOCK MODE statement while the SET LOCK MODE is set by the end user application CDR_
3. ALL A shaded option is the default action Syntax within a pair of arrows indicates a subdiagram The vertical line terminates the command f ate OFF ON A branch below the main path indicates an optional path Any term on the main path is required unless a branch can circumvent it Cee variable A loop indicates a path that you can repeat Punctuation along the top of the loop indicates the separator symbol for list items ge A gate 3 ona path indicates that you can only use that path the indicated number of times even if it is part of a larger loop You can specify size no more than three times within this statement segment 2 of 2 Introduction 11 Sample Code Conventions setenv How to Read a Command Line Diagram Figure 1 shows a command line diagram that uses some of the elements that are listed in the previous table Figure 1 Example of a Command Line Diagram INFORMIXC A nr ES pathname To construct a command correctly start at the top left with the command Follow the diagram to the right including the elements that you want The elements in the diagram are case sensitive Figure 1 illustrates the following steps 1 Type setenv 2 Type INFORMIXC 3 Supply either a compiler name or a pathname After you choose compiler or pathname you come to the terminator Your command is complete 4 Press RETURN to execute the comm
4. a a 4 3 ane omas n e Read only privileges Figure 4 3 Workload Partitioning in a Primary Target Replication System In Figure 4 3 the replication model matches the partition model for the employee tables The Asia Pacific computer owns the partition and can therefore update insert and delete employee records for personnel in its region The changes are then propagated to the U S and European regions Asia Pacific can query or read the other partitions locally but cannot update those partitions locally This strategy applies to other regions as well Order entry custno custname 1234 XYZLID 1235 XSPORTS Order processing Workflow Replication Workflow Replication Unlike the data dissemination model in a workflow replication system the data moves from site to site Each site processes or approves the data before sending it on to the next site Figure 4 4 l Inventory A Workflow Accounting management Ship Replication System custno custname custno custname custno custni TA XZD T XZD Where Update 1235 XSPORTS 1235 XSPORTS 1235 XSPORTS Authority Moves Order Order Order From Site to Site processing processing processing Figure 4 4 illustrates an order processing system Order processing typically follows a well ordered series of steps orders are entered approved by accounting inventory is recon
5. Server X Server Y Server Z server server server Synchronous data replication is appropriate for applications that require immediate data synchronization However synchronous data replication requires that all hardware components and networks in the replication system be available at all times It is difficult to guarantee the constant avail ability of all devices in a replication system because hardware components and networks fail For more information about synchronous replication refer to the discussion of two phase commit in your Administrator s Guide Asynchronous Data Replication Asynchronous data replication updates the databases that reside at a repli cated site after the primary database has committed the change The delay to update the replicated site databases can vary depending on the business application and user requirements However the data eventually synchro nizes to the same value at all sites The major benefit of this type of data replication is that if a particular database server fails the replication process can continue and the original transaction is not directly affected by replication 1 4 Guide to Informix Enterprise Replication Data Replication Capture Mechanisms Asynchronous replication allows the following different replication models m Primary target All database changes originate at the primary database and are replicated to the target databases Changes at the target databases a
6. To use ERM with Dynamic Server Version 7 31 install Informix Enterprise Command Center IECC From IECC choose Tools gt Enterprise Replication Manager To use ERM with Dynamic Server Version 9 2 install ERM and the proper connectivity tools For information about preparing ERM for Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction You can perform all the operations that are described in this chapter with the command line utility CLU described in Chapter 11 or with the application programming interface API calls described in Chapter 12 Enterprise Replication Menus 8 5 General Information UNIX WIN NT General Information This section discusses some general information that you need before you work with ERM Preparing to Use the Replication Manager Before you can use ERM you must prepare SOLHOSTS connectivity infor mation for the database servers and database server groups The sqlhosts file for each database server contains connectivity information about every database server and database server group that participates in replication For information about preparing the sqlhosts file refer to your Administrator s Guide With Dynamic Server Version 7 31 use the Add Database Server wizard in Informix Enterprise Command Center IECC to prepare the SOLHOSTS connectivity information With Dynamic Server
7. 8 36 Guide to Informix Enterprise Replication Figure 8 12 Help Topics Dialog Box Using Help Accessing Context Sensitive Help At any time you can choose one of the following options to obtain help m Click the What s This icon in the title bar m Select an object and press F1 ERM provides additional information for all toolbar objects When you point to an object on the toolbar information about that object automatically appears in the status bar Using Help Using Help is a user s guide to Windows Help Contacting Informix The Contacting Informix option contains information on how to contact Informix Technical Support and other departments About Replication Manager The About Replication Manager option displays the Version Number Serial Number name of the principal contact and the licensing organization and Informix trademark information It also lists special rights and regulations with respect to government regulations Enterprise Replication Menus 8 37 Hierarchical View Menus are available Menu Hierarchical View Menus When a Hierarchical Routing View window is active the following menus Options File Edit Server View Window Help 8 38 Guide to Informix Enterprise Replication Lets you print the hierarchy display or save a text report that lists the servers their types and their parent servers The menu also lets you close the window or exit from ERM
8. At least one thread is created for each CPU virtual processor VP The maximum number of threads is 2 number of CPU VPs Schedules internal Enterprise Replication events 2 of 2 Environmental Considerations You need to evaluate various factors for your environment Each replication system that you create affects your environment Time Synchronization Any time you use replication that requires conflict resolution the operating system times of the database servers that participate in the replicate must be synchronized For tools for synchronizing the times refer to the manuals for your particular operating system Setting Up Your Replication Environment 5 9 Transaction Processing Effect Transaction Processing Effect Many variables affect the impact that replicating data has on your transaction processing This section discusses some of these variables Using Unbuffered Logging Informix recommends that you replicate tables only from databases created with unbuffered logging Enterprise Replication evaluates the logical log for transactions that modify tables defined for replication If a table defined for replication resides in a database that uses buffered logging the transactions are not immediately written to the logical log but are instead buffered and then written to the logical log in a block of logical records When this occurs Enterprise Repli cation evaluates the buffer of logical log records all at once
9. 12 40 Guide to Informix Enterprise Replication cdr_stop_car cdr_stop_cdr The cdr_stop_cdr function stops Enterprise Replication processing Syntax include cdrapi h int cdr_stop_cdr Usage In most situations Enterprise Replication starts when cdr_define_serv is first executed from a database server The Enterprise Replication threads remain running until the database server is shut down or until the local database server is deleted with the cdr_delete_serv call If you shut down the database server while Enterprise Replication is running Enterprise Repli cation restarts when you restart the database server Under rare conditions users might want to temporarily stop the Enterprise Replication threads without stopping the database server The cdr_stop_cdr function shut downs all Enterprise Replication threads in an orderly manner When cdr_stop_cdr completes the shutdown it writes the message CDR shutdown complete in the database server log file After you issue a cdr_stop_cdr function Enterprise Replication threads remain stopped even if the database server is stopped and restarted To restart Enterprise Replication see cdr_start_cdr on page 12 38 Warning Informix recommends that you issue cdr_start_cdr and cdr_stop_cdr with extreme caution Use these functions during a period of little or no database activity and keep the Enterprise Replication downtime to a minimum Transacti
10. Enterprise Replication Features 2 11 Participant Participant A participant is an entity within a replicate A replicate contains two or more participants The participant specifies the data that should be replicated for a single table on a single database server A participant includes the following information Database server Database in which the table resides Table name Table owner SELECT statement Participant type optional The database server database table name and table owner specify the source of the data The SELECT statement in a participant has the following Characteristics The columns selected must include a primary key The statement can reference only a single table The statement cannot include a join or a subquery The statement can include an optional WHERE clause The participant type can be either primary target or update anywhere The default mode is update anywhere Replicate Group A replicate group combines several replicates that have identical participant database servers Replicate groups provide two major benefits m Ease of use through easier administration m Increased performance with parallel processing 2 12 Guide to Informix Enterprise Replication Replicate Group Ease of Use If your replication system contains many replicates for example a hundred replicates that are controlled identically when you define a replicate group you can use a single command to star
11. Guide to Informix Enterprise Replication Version 9 2 September 1999 Part No 000 6208 Published by Informix Press Informix Corporation 4100 Bohannon Drive Menlo Park CA 94025 1032 1999 Informix Corporation All rights reserved The following are trademarks of Informix Corporation or its affiliates one or more of which may be registered in the United States or other jurisdictions Answers OnLine C ISAM Client SDK DataBlade Data Director Decision Frontier M Dynamic Scalable Architecture Dynamic Server Dynamic Server Developer Edition Dynamic Server with Advanced Decision Support Option Dynamic Server with Extended Parallel Option Dynamic Server with MetaCube Dynamic Server with Universal Data Option Dynamic Server with Web Integration Option Dynamic Server Workgroup Edition Dynamic Virtual Machine Enterprise Decision Server Formation Formation Architect M Formation Flow Engine Gold Mine Data Access TIF 2000 i Reach i Sell Mustra9 Informix Informix 4GL Informix Inquire Informix Internet Foundation 2000 InformixLink Informix Red Brick Decision Server Informix Session Proxy Informix Vista InfoShelf Interforum I Spy Mediazation MetaCube NewEra ON Bar OnLine Dynamic Server OnLine Secure Dynamic Server OpenCase Orca PaVER Red Brick and Design R
12. If you use a non U S English locale you might need to explicitly provide the locale and conversion files For more information about how to use GLS refer to Informix Guide to GLS Functionality 5 16 Guide to Informix Enterprise Replication Preparing Data for Replication In This Chapter Preparing Consistent Data Shadow Columns Using the High Perom Tander Using the onunload and onload Utilities Using the dbexport and dbimport Utilities Using the UNLOAD and LOAD statements Blocking Replication Data Preparation Examples Adding a New Participant to an Existing Replicate Beginning Work Without Replication Using DB Access to Begin Work Without Replication Using ESQL C to Begin Work Without Replication 6 3 6 3 6 4 6 4 65 65 65 6 6 6 8 6 9 6 10 6 10 6 2 Guide to Informix Enterprise Replication In This Chapter The goal of data replication is to provide identical or at least consistent data on multiple database servers This chapter describes how to prepare the information in your databases for replication When you define a new replicate on tables with existing data on different database servers the data might not be consistent Similarly if you add a participant to an existing replicate you need to ensure that all the databases in the replicate have consistent values You might also need to take special steps when you recover data For example if a dbspace fills u
13. Receive queues are stably stored only when Enterprise Replication receives very large transactions The receive queues usually do not require as much space as the send queue The send and receive queue dbspaces default to the root dbspace You cannot change the send and receive queue dbspaces after you define repli cation for the database server For an active replication environment you should create dbspaces for the send and receive queues before you define the replication server and assign the queues to those spaces If the root dbspace fills the Enterprise Replication and other database servers become unavailable The CDR_QUEUEMEM configuration parameter affects the amount of memory space that is available for the message queues For information about CDR_QUEUEMEM refer to Appendix A Configuration Parameters 5 6 Guide to Informix Enterprise Replication Delete Tables Delete Tables Enterprise Replication creates delete tables only if you use time stamp and or a procedure written in SPL Stored Procedure Language as your conflict resolution rules Delete tables keep track of modified rows and are used for conflict resolution Enterprise Resolution creates and manages these tables Neither the end user nor the database administrator interacts directly with the delete tables Delete tables are created on the database server where the data originates and on all the database servers to which data gets replicated
14. Similarly when you remove a replicate from the replicate group the data queued for the entire group is immediately sent to the targets The replicate that you removed from the group maintains the frequency attributes of the replicate group That is the replicate that you remove from the group inherits the frequency attributes of the replicate group After a replicate is defined as part of a replicate group you must use replicate group control commands for control and configuration You cannot control the replicate individually until either the replicate is removed from the replicate group or the replicate group is deleted API Functions 12 13 cdr_define_reol cdr_define_repl The cdr_define_repl function defines a replicate in the global catalog Syntax include cdrapi h int define_repl repl_name attrs mflags participants which char repl_name CDR_repl_attrs attrs uint4 mflags CDR_plist participants void which repl_name is the name of the replicate to define attrs are the replicate attributes mflags are the definition flags participants are the participating database servers and associated attributes which points to information if an error occurs See Using the Stored Error Information on page C 1 Usage The cdr_define_repl function defines the replicate rep _name with attributes attrs and participants participants in the global catalog For definitions of the CDR_repl
15. The options in cdr change group have the meanings that the following table shows Options Long Form Short Form Meaning add a Add replicate s to a group delete d Remove replicate s from a group Usage Use this command to add replicates to a group or to remove replicates from a group 11 20 Guide to Informix Enterprise Replication cdr change group You cannot remove replicates from a group when the group is suspended Also you cannot add a suspended replicate to a group even if the group is also suspended Examples The following example adds the replicates house and barn to group newprod cdr change group add newprod house barn The following example removes the replicates teepee and wigwam from group favorites cdr cha gro del favorites teepee wigwam Command Line Utility 11 21 cdr change replicate cdr change group Element modifier participant replicate cdr change replicate The cdr change replicate command allows you to modify an existing replicate by adding or deleting one or more participants Syntax add replicate participant modifier p 11 8 delete replicate participant Purpose Restrictions Specifies the rows and columns See Restrictions on the SELECT Participant to replicate Statement on page 11 11 Modifier p 11 11 Specifies the database server and The participant must exist Participant p 11 9 table for replication Name of the repl
16. select from stock A 3 stores g_italy informix stock select from stock 4 cdr list replicate 5 cdr list replicate repl2 6 cdr define server connect japan init sync g_usa g_japan 7 cdr list server 8 cdr change replicate add repl2 9 stores g_japan informix stock select from stock 10 cdr list replicate repl2 11 cdr start replicate repl2 12 cdr list replicate Replication Examples 3 9 Preparing for an Update Anywhere Replication Lines 1 through 3 Lines 1 through 3 define a replicate These lines are all one command The backslashes at the end of lines 1 and 2 indicate that the command continues on the next line Line 1 names the replicate rep12 and specifies that conflicts should be ignored Line 2 describes one participant in the replicate It specifies the table and the columns to replicate on database server usa Line 3 describes a second partic ipant in the replicate It specifies the table and the columns to replicate on database server italy If any data in the selected columns changes on either participant that changed data should be sent to the other participants in the replicate The replicate definition could also include japan but this example adds japan in a separate step on lines 8 and 9 Line 4 This line displays all the replicates so that you can verify that your definition of repl2 succeeded The command returns the following information REPLICATE STATE CONFL
17. triggers are not invoked Y conversion to canonical form is required no canonical form used 2 of 2 The syscdrs table contains information about database servers that have been declared to Enterprise Replication Column Type Description servid integer Server identifier servname char 128 Database server name cnnstate char 1 Status of connection to this database server C Connected D Connection disconnected will be retried T Idle time out caused connection to terminate X Connection closed by user command Connection unavailable until reset by user cnnstatechg integer Time that connection state was last changed servstate char 1 Status of database server A Active S Suspended H Holding Q Quiescent initial sync state only 1 of 2 SMI Tables for Enterprise Replication B 13 syscarsend_ buf Column Type Description ishub char 1 Y the server is a hub N the server is not a hub A hub is any replication server that forwards infor mation to another replication server isleaf char 1 Y the server is a leaf server N the server is not a leaf server rootserverid integer The identifier of the root server forwardnodeid integer The identifier of the parent server timeout integer Idle timeout 2 of 2 Although not directly connected a nonroot server is similar to a root server except it forwards all replicated messages through its parent root server All nonroot servers are known to
18. Environment for the Replication Examples UNIX WIN NT The UNIX sqlhosts file for each database server contains the following connectivity information g_usa group 5 i 1 usa ontlitcp sl techpubsl g g_usa g_italy group i 8 italy ontlitcp s2 techpubs8 g g_italy g_japan group i 6 japan ontlitcp s3 techpubs6 g g_usa With Dynamic Server Version 7 31 use the IECC Add Database Servers wizard to prepare the SQLHOSTS connectivity information With Dynamic Server Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction for information about preparing the SQLHOSTS connectivity information All commands in this example except for creation of the sample databases on italy and japan are issued from the computer s1 The databases for the examples in this chapter are identical stores_demo databases with logging as follows Create a database named stores on the usa database server sl gt dbaccessdemo log stores Create a database named stores on the italy database server s1 gt rlogin s2 s2 gt dbaccessdemo log stores Create a database named stores on the japan database server sl gt rlogin s3 s2 gt dbaccessdemo log stores 3 4 Guide to Informix Enterprise Replication Terminology Terminology Enterprise Replication and ERM deal with the following three distinct objects that are treated almost as sy
19. Figure 1 2 Trigger Based Transaction Capture Affects the Performance of the Original Transaction Source database server Item Total Price Widget A 15 00 Widget B 4 Step 1 A transaction updates a table 43 00 Widget C 100 00 A Step 2 The update of the rows causes the replication trigger to fire SPL procedure Step 3 Thetrigger invokes aprocedure that updates the change queue a SQL oe SEPEN A The original transaction might regain control after the procedure is invoked which would make steps 4 and 5 background activities lt Ste 4 The replication system uses a procedure to send updates to the target table Target database server Qty Total Price 3 15 00 qx i 1 43 00 Step 5 The transaction updates the target table Data Replication Overview 1 7 Log Based Data Capture Log Based Data Capture Enterprise Replication uses log based data capture Log based data capture takes changes from the logical log and does not compete with transactions for access to production tables Log based data capture systems operate as part of the normal database logging process and add minimum overhead to the system However not all log based replication systems are the same Log based replication systems that use external database servers and processes offset the advantages of log based transaction capture because of the additional data
20. For more infor mation see Chapter 10 Use attrs sendq for the send queue dbspace The send queue is assigned to a particular dbspace The send queue dbspace cannot be a temporary dbspace The path for the send queue dbspace must be no longer than 128 bytes Use attrs syncServ as the database server for catalog synchroni zation when the database server is initialized This option is only available when the A_INIT flag has been set API Functions 12 19 cdr_delete_group cdr_delete_group The cdr_delete_group function deletes a replicate group Syntax include cdrapi h int cdr_delete_group group time char group time_t time unused group isthe replicate group name time is not used but cannot be omitted Use t ime_t 0 for that argument Usage The cdr_delete_group function deletes the replicate group group from the global catalog The cdr_delete_group function does not affect the replicates or associated data When a replicate group is deleted the state of individual replicates within the group is unchanged 12 20 Guide to Informix Enterprise Replication cdr_delete_repl cdr_delete_repl The cdr_delete_repl function deletes a replicate from the global catalog Syntax include cdrapi h int cdr_delete_repl repl time char repl time_t time unused rep is the name of the replicate to delete time is not used but cannot be omitted Use time_t 0 f
21. Participant Properties Enterprise Replication Menus 8 19 Group Menu Group Menu The Group menu lets you define and control replicate groups and review replicate group properties All items on the Group menu are available in both expert and nonexpert modes The Group menu has the following options Define Group Delete Group Add Replicate s Remove Replicate Start Group Stop Group Suspend Group Resume Group Group Properties Defining a Replicate Group To define a replicate group choose Group Define Group ERM starts the Define Replicate Group wizard The Define Replicate Group wizard provides a series of pages that guide you through the process to define a replicate group For information about this wizard refer to Defining a Replicate Group on page 9 15 To define a replicate group using the CLU refer to cdr define group on page 11 25 M odifyi ng Grou PS After you define at least one replication group you can use the choices on the Group menu to modify the groups 8 20 Guide to Informix Enterprise Replication Modifying Groups Deleting a Replicate Group To delete a replicate group select the replicate group Choose Group Delete Group When Enterprise Replication receives this command it deletes the replicate group from the global catalog The Delete Group command does not affect the replicates or the associated data in the replicate group If you have time based replicat
22. Procedure Example The procedure determines the type of collision If a replication order error is detected the replicated row is not applied but is logged Otherwise if the replicated salary field is not equal to the local target the replicated row is applied but is not logged create procedure updateSalary localServer CHAR 18 localTS DATETIME YEAR TO SECOND localDelete CHAR 1 replServer CHAR 18 replTS DATETIME YEAR TO SECOND replDbop CHAR 1 localEmpNum INT localEmpName CHAR 15 localSalary INT replEmpNum INT replEmpName CHAR 15 replSalary INT returning CHAR 1 INT INT CHAR 15 INT Do nothing if replicated row is out of logical order 1 if local row is found in the deleted row table and the replicated operation is update or delete 2 if local row is found in target table and the replicated operation is insert Enter the row to log if localDelete Y then if replDbop U or replDbop D then return 0 100 null null null end if if replDbop I then return 0 101 null null null end if If the replicated row is from server corporate and the the local row s salary field is not equal to the replicated salary field then update local row if replServer corporate and localSalary replSalary then return replDbop 200 replEmpNum replEmpName replSalary else return replDbop 201 replEmpNum replEmpName loca
23. The struct column in the following table indicates the structure where error information will be stored cdr_define_group cdr_define_repl cdr_modify_replmode cdr_participate_group cdr_participate_repl cdr_resume_serv cdr_start_group cdr_start_repl cdr_stop_group cdr_stop_repl cdr_suspend_serv Definition of Return Codes List of Return Values Mnemonic CDR_SUCCESS CDR_ENOCONNECT CDR_ECOLUNDEF CDR_ECOMPAT CDR_ECONNECT CDR_EDBDNE CDR_EDBLOG CDR_EFREO CDR_ECONNECTED CDR_EGRPSTATE CDR_EGRPUNDEF CDR_EGRPUNIO CDR_EIDLE CDR_EINVOP CDR_ENOPART CDR_ENOPKEY Numeric Value 7 8 Description struct Command was successful A connection does not yet exist for the given server not in use Table column undefined Incompatible server version Unable to connect to server specified Database does not exist CDR_plist Database not logged CDR_plist Bad or mismatched frequency attributes CDR_idlist The frequency type specified is incorrect or the values are out of range for the frequency type specified A connection already exists for the given server Illegal group state change Undefined group Group name already in use Invalid idle time specification Invalid operator or specifier not in use not in use Participants required for operation specified Table does not contain primary key CDR_plist 1 of 6 C 2 Guide to Informix Enterprise Replication Definit
24. You can start and stop each replicate individually 1 Start replication for the replicate that you just defined repl1 urban gt cdr start repl c hill repll Verify that the replication is active Execute cdr list replicate again and verify that the STATE column has changed from INACTI to ACTIVE At this point replication is active but no database activity has occurred Use DB Access to make a change to the hill database INSERT INTO customer VALUES 0 alice adams Aardvark 121 First Street Atlanta IN 47904 317 463 5555 Use DB Access to verify that the change to hill_db database is reflected on the lake_db database SELECT FROM lake_db lake customer WHERE fname alice Command Line Utility Syntax The next sections show the syntax for all the variations of the cdr CLU The error messages that Enterprise Replication returns when a command fails are documented in Appendix C Command Line Utility 11 19 cdr change group cdr change group The cdr change group command changes a replicate group by adding or deleting replicates Syntax repl_ group Gees E cdr change group add Connect Option S a delete yg p 11 8 Element Purpose Restrictions repl_group Name of the replicate group to The replicate group must exist Identifiers p 8 8 change replicate Name of the replicate s to addto The replicate s must exist Identifiers p 8 8 or delete from the group
25. control queue is a stable queue that contains control messages for the replication For information on the columns of the syscdrctrl_txn table refer to Columns of the Transaction Tables on page B 3 B 6 Guide to Informix Enterprise Replication syscdrerror syscdrerror The syscdrerror table contains information about errors that Enterprise Replication has encountered Column errornum errorserv errorseqnum errorstmnt error time sendserv reviewed syscdrgrp Type integer char 128 integer char 128 datetime year to second char 128 char 1 Description Error number Database server name where error occurred Sequence number that can be used to prune single error table Error description Time error occurred Database server name if applicable that initiated error behavior Y if reviewed and set by DBA N if not reviewed The syscdrgrp table contains replicate group information Column Type Description grpname char 218 Replicate group name isseq char 1 Y if sequential N if non sequential SMI Tables for Enterprise Replication B 7 syscargrppart grpname servername state syscdrgrppart syscdrpart Type char 128 char 128 integer The syscdrgrppart table contains replicate group information Column Description Replicate group name Database server name The following state values apply when the OR operator is applied 0x0000 Defined
26. replicates you want to participate in the replicate group The Replicates box lists all defined replicates Select the replicates for your replicate group Figure 9 11 Select Replicates for the Replicate Group Define Replicate Group Wizard When you have selected all the replicates for the group click Finish The wizard creates the replicate group for you Generic Configuration Wizard The Generic Configuration wizard lets you create several replicates that have the same characteristics at the same time This saves you from the work of creating each replicate individually To access the Generic Configuration wizard choose File gt New Script gt Object gt Generic Configuration Wizards You can create either update anywhere replicates or primary target replicates Enterprise Replication Manager Wizards 9 17 Choosing a Naming Scheme Choosing a Naming Scheme The wizard asks you to choose a naming scheme for the replicates that it will create Generated replicate names can be up to 128 bytes long The name must start with an alphanumeric character and contain only alphabetic and numeric characters and underscores Figure 9 12 shows the naming dialog box for update anywhere replicates Figure 9 12 Update Anywhere Naming Dialog Box Update Anywhere Replication System Wizard robe Table Database Owner Naming Update Anywhere Replicates For generic update anywhere replicates the generated names have two p
27. which consumes excess CPU time and memory When you define a table for replication in a database created with unbuffered logging Enterprise Replication can evaluate the transactions as they are produced Analyzing Replication Volume Determine how many data rows change per day For example an application issues a simple INSERT statement that inserts 100 rows If this table is repli cated these 100 rows must be propagated and analyzed before they are applied to the targets Using Complex SELECT Statements Evaluate the complexity of the SELECT statement that specifies the data for replication If you define your replication system with a SELECT Enter prise Replication is optimized and immediately continues to process If your SELECT statement includes a WHERE clause Enterprise Replication must evaluate the WHERE clause which can affect performance 5 10 Guide to Informix Enterprise Replication Enterprise Replication Data Types Enterprise Replication Data Types Enterprise Replication supports all Informix defined data types It also provides limited support for user defined data types Enterprise Replication does not support optical devices If you use SERIAL or SERIAL8 data types you must define the serial columns only on the primary server On the secondary server s the columns must be integers The following sections describe how Enterprise Replication captures evaluates and distributes simple large objec
28. 28 00 2 00 Normal Demand Moderate Value RS s154 390 96 05 29 23 26 20 833437580 RD 10 Digitizer 319 A Apple Toyota Digiti 2 00 2 00 Normal Demand Moderate Value RH Row 3 Collection Id 24707080 Rep toresecdr customer DbOp Update H CDR 14 Failed conflict resolution ru S ctr0 377 96 05 29 23 26 35 833437595 D 18 Larraine Hustin 2021 South Blvd I Duwi PHwWiowwor S s1s4 390 96 05 29 23 26 22 833437582 D 18 Larraine Hustin 2021 South Blvd A Pror DDODDADD 10 12 Guide to Informix Enterprise Replication lt 500 NoChange TEXT PB 877 necromsv 840338478 96 08 17 20 21 18 gt where NoChange after 500 indicates the TEXT data has size of 500 but the data has not been changed on the source server Therefore the data is not sent The following output provides some examples of RIS files TXH Source 1D 390 Name s1s4 CommitTime 96 05 29 23 26 24 TXH Target 1D 392 Name purl ReceiveTime 96 05 29 23 27 16 icate Id 24707077 Table e SQL 0 ISAM 0 D 20 VGA Card 439 A Acer Chevrolet VGA Card 439 422 00 538 00 994 00 13 00 13 00 8 00 Normal Demand Moderate Value Item RRD 20 VGA Card 439 A Acer Chevrolet VGA Card 439 422 00 538 00 788 00 13 00 12 00 8 00 Normal Demand Moderate Value Item icate Id 24707077 Table e SQL 0 ISAM 0 zer 319 29 00 36 00 552 00 28 0 Item zer 319 29 00 36 00 581 00 28 0 tem icate Id 24707080 Table e SQL 0 I
29. 3 list of commands 11 5 participant modifier 11 11 participant syntax 11 9 terminology 11 3 Comment icons Intro 9 Complex transactions evaluating images D 1 Compliance with industry standards Intro 16 Configuration parameters 5 8 CDR_DSLOCKWAIT A 2 CDR_EVALTHREADS A 3 CDR_LOGDELTA A 4 CDR_NIFCOMPRESS A 5 CDR_NIFRETRY A 7 CDR_QUEUEMEM A 7 list of A 1 Conflict resolution information 8 18 optimize behavior 11 29 12 17 options 11 28 Conflict resolution rule ignore 7 20 stored procedure 7 17 time stamp 7 15 valid combinations 7 13 Conflict resolution scope row by row 7 14 transaction 2 16 7 14 Connectivity information sqlhosts See Sqlhosts information S T U VW X Y Z Constraint checking 7 14 Contact information Intro 16 Conventions documentation Intro 7 D Data delivery resume 11 61 11 62 11 63 12 35 12 36 12 37 suspend 11 73 11 75 11 77 12 44 12 45 12 46 Data dissemination model 4 4 Data replication asynchronous 1 4 1 5 capture mechanisms log based data capture 1 8 trigger based transaction capture 1 6 key elements 1 8 synchronous definition of 1 3 trigger based data capture 1 6 Data types BYTE and TEXT 5 11 floating point 5 11 SERIAL and SERIAL8 5 11 Database server connect to 3 7 3 24 11 24 disconnect from 11 43 listing 11 50 modify attributes 11 59 register for Enterprise Replication 11 33 12 18 remove from Enterprise Replication 8 30 11 40 12 22 resume data delivery 11 63 12
30. 37 suspend data delivery 11 77 12 46 Database server groups 3 4 3 5 8 6 11 12 12 3 E 4 Data consolidation model 4 5 DB Access utility Intro 5 DBSERVERALIASES 3 5 11 12 12 3 A 1 DBSERVERNAME 11 12 12 3 A 1 dbspace delete tables 5 7 error table 11 44 12 30 message queues 5 6 A BC DEFGH receive queue 3 21 11 35 11 36 12 19 send queue 11 35 11 36 12 19 Default locale Intro 5 Delete database server from Enterprise Replication 11 40 12 22 participant from replicate 11 22 12 32 replicate 11 39 12 21 replicate from group 11 20 12 31 replicate group 11 38 12 20 Delete table definition of 5 7 7 12 in conflict resolution 7 15 7 18 Demonstration databases Intro 5 Dependencies software Intro 4 directory 3 21 Documentation notes Intro 15 Documentation types of documentation notes Intro 15 error message files Intro 14 machine notes Intro 15 on line help Intro 14 on line manuals Intro 13 printed manuals Intro 14 related reading Intro 16 release notes Intro 15 E en_us 8859 1 locale Intro 5 Enterprise Replication threads list of 5 8 Environment variables Intro 8 Error management 12 23 12 30 12 33 12 34 Error message files Intro 14 Error messages Enterprise Replication C 1 Error table dbspace 11 44 12 30 description 12 7 management 11 44 12 33 12 34 Expert mode description of 8 33 JK L MN OP QRS TU VW X Y Z F Feature icons Intro 9 Features of this product new Intro 6 Find Error
31. Anywhere Replication System Washington service center Update gt NewYork y 7 gt service center A server x Update server A seve 7 l Los Angeles ba E service center all Figure 4 1 illustrates an update anywhere replication system Because each service center can update a copy of the data conflicts can occur when the data is replicated to the other sites To resolve update conflicts you must provide conflict detection and conflict resolution rules Facts to Consider Review the following information before you select your update anywhere replication system Selecting Data for Replication The requirements for unique primary keys limit the use of serial keys in repli cation environments A serial column key cannot be a primary key by itself The primary key must include at least one additional column besides the serial column The additional column must make the combination of the additional column and the serial column globally unique across all database servers that participate in the replication system For example the additional column might be the location of the database server Selecting Enterprise Replication Systems 4 9 Facts to Consider When Enterprise Replication applies rows that contain a serial data column at a target database server the serial column value is set to the value assigned at the source database server Administering the Replication System Update anywhere replication
32. COMMIT WORK 7 8 Guide to Informix Enterprise Replication Evaluating Replication Examples Figure 7 6 Insert Followed by An Update Evaluation Logic Replicate Replicate Primary Key Send to Destination Initial Image Evaluates Final Image Evaluates Changed Database Server INSERT TorF UPDATE T yes or no INSERT with final row image The replicate WHERE clause imposes the restriction that only rows with the exempt column equal to N are replicated Enterprise Replication evaluates the transaction an insert followed by an update and converts it to an insert to propagate the updated image the final image In Figure 7 7 Enterprise Replication uses the logic in Figure 7 8 to evaluate whether any information is sent to the destination database server Figure 7 7 dallas_office phoenix_office Update Not lected t SELECT emp_id salary FROM employee WHERE exempt N op aie i BEGIN WORK BEGIN WORK INSERT INTO employee UPDATE employee VALUES 927 Jones SET EXEMPT N WHERE emp_id 927 COMMIT WORK COMMIT WORK Figure 7 8 Update Not Selected to Selected Evaluation Logic Replicate Replicate Primary Key Send to Destination Initial Image Evaluates Final lmage Evaluates Changed Database Server UPDATE F UPDATE T yes or no INSERT with final row image Enterprise Replication Processes 7 9 Evaluating Primary Key Updates The example shows a r
33. Lets you search for a specific replication server Lets you connect to or disconnect from the selected server It also shows the same Server Properties dialog box as the Server gt Server Properties choice from the ERM main window Lets you expand the hierarchical view to show all the repli cation servers or collapse view to one line The menu also lets you display or suppress the Toolbar and the Status Bar Offers the same options as the Window menu of the ERM main window except that it does not let you toggle between expert and nonexpert modes Offers the same options as the Help menu of the ERM main window Replication Scripting View Menus Replication Scripting View Menus When a Replication Scripting View window is active the following menus are available Menu Options File Lets you open save merge or print replication scripts Object Allows you to select an object replicate participant group or server to add to the script to rename an object or to use the Generic Configuration Wizard For information about the Generic Configuration Wizard refer to Generic Config uration Wizard on page 9 17 Edit Lets you search for a specific replication server View Lets you expand or collapse the display and switch between different display formats The menu also lets you display or suppress the Toolbar and the Status Bar Window Offers the same options as the Window menu of the ERM main window except th
34. M 10 50 A M 10 55 A M 11 00 A M 11 05 A M A stop replicate issued At the logical log time 10 45 A M Enterprise Replication begins to read logical log records that are marked for replication At 11 00 A M the user issues a Stop Replicate command to stop the replication of data in a replicate Enterprise Replication refers to the time at which replication stops Enter prise Replication evaluates all transactions that were committed between 10 45 A M and 11 00 A M and passes them to Enterprise Replication for evaluation 7 4 Guide to Informix Enterprise Replication Evaluating Images of a Row Enterprise Replication does not replicate any transactions that are committed after 11 00 A M For example Transaction A in Figure 7 1 is not passed to Enterprise Replication Although the transaction starts at 10 55 A M it does not complete until 11 04 A M and therefore does not commit before the cut off time of 11 00 A M Evaluating Images of a Row Enterprise Replication evaluates the initial and final images of a row and any changes that occur between the two row images to determine which rows to replicate Each row image contains the data in the row as well as the action performed on that row Enterprise Replication evaluates the images of a row in parallel to assure high performance Enterprise Replication collects records that qualify for repli cation into a transaction list and passes them to the Enterprise Replicati
35. Page Define Replicate Wizard Enterprise Replication Manager Wizards 9 11 Defining Participant Attributes Defining Participant Attributes The wizard page in Figure 9 7 asks you to define the table you want to replicate the owner of the table the name of the database in which the table resides and whether to use the table owner to apply permissions Figure 9 7 Participant Attributes Page Define Replicate Wizard stores informix The DB Browser button opens a Database Query window that allows you to browse through the databases of the database server of the participant You can use the Database Query window to select the database table and columns for the participant 9 12 Guide to Informix Enterprise Replication Choosing the Columns to Replicate Choosing the Columns to Replicate The wizard page in Figure 9 8 lets you select columns for replication and if desired restrict the data replicated with a WHERE clause You can also use the DB Browser button on this page to browse through databases and select columns Figure 9 8 Select Columns Page Define Replicate Wizard item_num order_num stock_nurn where manu_code HRO You can perform column mapping with your column selection Each partic ipant in the replicate must define the identical number of columns n to n mappings and the data types must be the same For more information see Column Mapping on page D 5 Enterpri
36. Replicate States on page 8 14 Example The following example connects to the default database server INFORMIXSERVER and resumes the replicate smile cdr resume repl smile 11 62 Guide to Informix Enterprise Replication cdr resume server cdr resume server The cdr resume server command resumes delivery of replication data to a database server Syntax cdr resume server server_ group p 11 8 Element Purpose Restrictions Syntax server_group Name of server group to resume The server group must be Server Group defined for replication and must p 11 12 be suspended Usage The cdr resume server command restarts suspended replication to the server server_group The server must have been previously suspended with the cdr suspend server command on page 11 77 Example The following example resumes replication on the server groups g_utah and g_iowa cdr resume serv g_utah g_iowa Command Line Utility 11 63 cdr start cdr start The cdr start command starts Enterprise Replication processing Syntax cdr start p 11 8 Usage Use cdr start to restart Enterprise Replication after you stop it with cdr stop When you issue cdr start Enterprise Replication brings up all connections to other adjacent replication servers and starts sending previously queued data Replication servers replicates and groups that were suspended before the cdr stop command was issued remain suspende
37. Suspended replicate groups still capture and accumulate database changes but do not transmit any of the captured data To change the state to suspended choose Group Suspend Group The data is queued and waits until the state is changed to active to transfer the captured data To change the state to active choose Group Resume Group All data accumulated during the suspended state is transferred and the database change capture continues and transmission resumes Warning When a replicate is suspended Enterprise Replication holds the replication data in the send queue until the group is resumed If lots of data is generated for this replicate while it is suspended the send queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize transactions if a replicate is suspended For example a transaction that updates tables X and Y will be split if replication for table X is suspended Enterprise Replication Menus 8 23 Viewing Replicate Group Properties Viewing Replicate Group Properties The Replicate Group Properties dialog box summarizes the properties that you assigned to a replicate group To view replicate group properties select the replicate group and then choose Group Group Properties ERM displays a dialog box that shows the properties of the replicate group as Figure 8 8 on page 8 24 illustrates Figure 8 8 Group Properties Dialog Box in Nonexpert Mode and in Expert Mode Repl
38. The onstat g ddr Command The g ddr option of the onstat command is an important status tool It prints the status of the Enterprise Replication database log reader The ddr refers to an internal component of Enterprise Replication that reads the log If log reading is blocked then data might not be replicated until the problem is resolved If the block is not resolved then the database server might overwrite the read position of Enterprise Replication which means that data will not be replicated Once this occurs you must manually resynchronize the source and target databases The onstat g dss Command The g dss option of the onstat command prints detailed information about the activity of individual data sync threads The onstat g dtc Command The g dtc option of the onstat command prints statistics about the delete table cleaner The g dtc option is used primarily as a debugging tool and by Informix Technical Support The onstat g grp Command The g grp option of the onstat command prints statistics about the grouper for debugging and technical support use The onstat g grp command has the following formats onstat g grp onstat g grp modifier Enterprise Replication onstat g Options F 3 The onstat g nif Command Modifier The modifier can have the values that the following table shows What the Command Prints A All the information printed by the G T P E R and S modifiers E Grouper ev
39. Transaction Heading RRH Replicated Row Heading RRS Replicated Row Shadow Columns RRD Replicated Row Data RIS file 10 6 Guide to Informix Enterprise Replication The first three characters in each line of the ATS spool file describe the type of information for the line as the following table defines Description Information from the transaction header that includes the sending server ID and the commit time the receiving server ID and the received time and any Enterprise Repli cation SOL or ISAM error information for the transaction Header information from the replicated rows that includes the row number within the transaction the group ID the replicate ID same as replicate group ID if replicate is not part of any replicate group the database owner and table name and the database operation Shadow column information from replicated rows that includes the source server ID and the time when the row is updated on the source server This line is printed only if the replicate is defined with a conflict resolution rule Replicated row data is the list of replicated columns in the same order as in the SELECT statement in the define replicate command Each column is separated by a l and displayed in ASCII format When the spooling program encounters severe errors for example cannot retrieve replicate id for the replicated row unable to determine the replicated column s type size or length it displays
40. Workflow replication model 4 7 Workload partitioning model 4 6 X X Open compliance level Intro 16 Symbols INFORMIXDIR etc sqlhosts See sqlhosts file
41. a brief summary of data in the queues and for which servers the data is queued Use the BRIEF modifier to quickly identify sites where a problem exists If large amounts of data are queued for a single server then that server is probably down or off the network The other modifiers of the onstat g rqm command are used primarily as a debugging tool and by Informix Technical Support The onstat g rqm command has the following formats onstat g rqm onstat g rqm modifier F 6 Guide to Informix Enterprise Replication The onstat g rqm Command The modifier can have the values that the following table shows Modifier What the Command Prints ACKO The ack Send Queue CNTRLO The sync Send Queue RECVQ The Receive Queue SENDQ The Send Queue SYNCQ The sync Send Queue FULL Full information about every memory transaction for every queue BRIEF Brief summary of the data in the queues and the replication servers for which the data is queued If a queue is empty no information is printed for that queue Enterprise Replication onstat g Options F 7 ABCDEFGH I JKLMNOPQRSTUVWWXxYze Index A Aborted transaction spooling ATS activate 11 30 11 36 11 56 change directory location 8 32 deactivate 11 56 12 26 definition of 7 20 description 10 3 directory 11 35 11 59 field in structure 12 7 Active state definition of 8 22 Add participant to replicate 8 14 11 22 12 32 replicate to g
42. all root servers and other nonroot servers A nonroot server can be a terminal point in a tree or it can be the parent for another nonroot server or a leaf server Nonroot and root servers are aware of all replication servers in the replication environment including all the leaf servers A leaf server is a nonroot server that has a sparse catalog A leaf server has knowledge only of itself and its parent server It does not contain information about replicates of which it is not a participant The leaf server must be a terminal point in a replication hierarchy syscdrsend_buf The syscdrsend_buf table contains buffers that give information about the send queue When a user performs transactions on the source database server Enterprise Replication queues the data on the send queue for delivery to the target servers The send queue is a semi stable queue A semi stable queue is a queue that is in memory until CDR_QUEUEMEM is reached and spooled thereafter For information on the columns of the syscdrsend_buf table refer to Columns of the Buffer Tables on page B 4 B 14 Guide to Informix Enterprise Replication syscdrsend_txn syscarsend_txn The syscdrsend_txn table contains information about the send queue When a user performs transactions on the source database server Enterprise Repli cation queues the data on the send queue for delivery to the target servers The send queue is a semi stable queue For information on the
43. an SPL statement the system level commands are executed as the table owner if the participant includes the O option If a trigger requires any system level commands the system level commands are executed as a less privileged user because on Windows NT you cannot impersonate another user without having the password whether or not the participant includes the O option Use the I option to disable the table owner option Using the P and R Options You can specify the mode of replication by using the P primary and R read only or target options with the participant If you do not specify either P and or R for the participants then the replicate is an update anywhere replicate For example in the following definitions replicate Rone is update anywhere while in replicate Rtwo serv2 is the primary and servl is read only cdr define repl c servl C timestamp S tran Rone Y db servl owner table select from table Y db serv2 owner table select from table cdr define repl c servl C ignore S tran Rtwo R db servl owner table select from table A P db serv2 owner table select from table For a discussion of primary and target servers refer to Primary Target Replication on page 2 15 11 10 Guide to Informix Enterprise Replication Participant Modifier Participant Modifier The participant modifier is a restricted SELECT statement The participant modifier specifies the rows and columns that will
44. associated SPL procedures Any changes to replication defini tions are automatically sent to other database servers in the replication system Data Replication Overview 1 11 How Enterprise Replication Replicates Data How Enterprise Replication Replicates Data Before you can replicate data you must declare a database server for repli cation and define replicates Declaring a database server for replication creates a database that keeps information about all servers in the replication system and about all data items that should be replicated Chapter 3 Repli cation Examples has simple examples of declaring replication servers and defining replicates For additional information refer to Chapter 5 Setting Up Your Replication Environment After the replicates are defined Enterprise Replication uses the following four major processes to replicate data Capture transactions Evaluate data for replication Distribute data for replication Apply replicated data Detailed information on each process is in Chapter 7 Enterprise Replication Processes 1 12 Guide to Informix Enterprise Replication Enterprise Replication Features In This Chapter Enterprise Replication Topologies Topology Terminology Replication Topology Types Fully Connected Hierarchical Tree Forest of Trees Enterprise Replication Objects Enterprise Replication Server Replicate Replicate Oplona Replicate St
45. at the same time Enterprise Replication provides conflict resolution rules for resolving conflicts The display in Figure 3 22 lets you specify the conflict rule For this example choose the default which is the ignore rule Click Next Figure 3 22 Select Conflict Resolution Rule 3 38 Guide to Informix Enterprise Replication Creating an Update Anywhere Replicate Specifying the Replication Options The wizard page in Figure 3 23 lets you specify options for the replicate You can leave the options set to the defaults that the wizard suggests Click Next Figure 3 23 Replication Options Specifying the Frequency When a change is made to a table that is participating in a replicate Enter prise Replication can propagate the change either immediately or at fixed intervals The choices for frequency are the same as those that Figure 3 12 on page 3 27 shows which are continuous or time based with continuous being the default Do not change the default settings Click Next Replication Examples 3 39 Creating an Update Anywhere Replicate Selecting the Participants On the Select Participants wizard page select the italy and usa servers and then click Add You could also select japan but one purpose of this exercise is to add japan to an already defined replicate Figure 3 24 shows the completed dialog box Click Next Figure 3 24 Select Participants 3 40 Guide to Informix Enterprise Replica
46. be used by someone other than yourself With the exception of the keyword transaction all keywords or letter combinations that modify the command options must be written as shown in the syntax diagrams For example in the Conflict Options on page 11 28 the option conf 11ct can be abbreviated but the keyword ignore cannot be abbreviated Both of the following forms are correct conflict ignore C ignore Order of the Options You can specify the options of the CLU commands in any order Some of the syntax diagrams in this chapter show the options in a specific order because it makes the diagram easier to read You can choose any order that you want for the options You should not repeat an option The following fragment is incorrect because c appears twice In most cases the CLU will catch this inconsistency and flag it as an error However if no error is given the database server uses the last instance of the option In the following example the database server uses the value c utah c ohio 1 500 c utah Tip Informix suggests that for ease of maintenance you always use the same order for your options Command Line Utility 11 7 Backslash Use Backslash Use Many CLU commands become quite long when all the options are included The examples in this chapter use a backslash 1 to indicate that a command continues on the next line The following two commands are equivalent The first command is too long to f
47. cdr_participate_group 2 we ee ee 12 31 cdr_participate_repl 2 2 1 ee ee 12 32 cdr_prune_errors 2 2 1 ee ee 12 33 cdr_prune_single_error 2 ww 12 34 cdr_resume_group ee ee ee ee 1285 cdr_resume_repl 2 2 2 2 a ee ee ee ew 12 36 cdr_resume_serv 2 2 ee ee ee ee 12 37 cdr_start_cdr 2 a dab a e 12 38 cdr_start_group 2 ee ee ee ee 12 39 cdr_start_repl 2 2 2 2 ee eee ee a o 1240 cdr_stop_cdr 2 2 ww ee ee 12 41 cdr_stop_group 2 2 ee ee ee 12 42 cdr_stop_repl 2 2 2 1 ee ee 12 43 cdr_suspend_group 2 ew 12 44 cdr_suspend_repl 2 a ee ee ee ee 12 45 cdr_suspend_serv 2 ee ew ee ee 12 46 EXAM ple ay ao a 1 e cae Ss SE ea he we Ge eS i AZ 12 2 Guide to Informix Enterprise Replication In This Chapter The application programming interface API allows Enterprise Replication to provide a single control point to configure and control replication objects Replication objects consist of database servers replicates and replicate groups Basic Information for APIs The next sections contain information that applies to all the API functions that this chapter discusses Database Server Groups All API functions except the cdr_connect option use the database server group name instead of the more familiar database
48. choose Start Replicate from the Replicate menu as Figure 3 19 shows Figure 3 19 Replicate Menu Start Replic ate 3 34 Guide to Informix Enterprise Replication Activating the Replicate When you select Start Replicate ERM displays the Start Replicate dialog box in Figure 3 20 Click Select All and then click OK Figure 3 20 Start Replicate Dialog Box Start Replicate ERM sets the state of all participants in rep13 to Active as Figure 3 21 shows TAR gt Figure 3 21 es Replication Manager g japan State of Participants a ria ts O E amk are in repl3 2 B oie g japan g_italy Active E ao g_usa primary Active Replication Examples 3 35 Cause a Replication Cause a Replication You can now modify the call_type table and observe the replication For example to insert a line into the call_type table on usa you can use DB Access as follows INSERT INTO stores usa stock VALUES 401 PRC ski boots 200 00 pair pair Observe the change on the italy database server SELECT from stores italy stock Do Not Cause a Replication Changes to the secondary participant italy in rep13 do not replicate to the primary usa For example to change a value in the call_type table on italy you can use DB Access as follows UPDATE stores italy call_type SET code_descr wrong size WHERE call_code C Verify that the change has not replicated to the call_ty
49. command also allows you to administer the cdr error table remotely The reviewed flag lets you watch for new errors while keeping the old errors in the table For example you could run cdr error periodically and append the output to a file Command Line Utility 11 45 cdr error Examples The following command displays the current list of errors on database server hill After the errors are displayed Enterprise Replication marks the errors as reviewed cdr error connect hill The following command connects to the database server lake and removes from the error table all errors that occurred before the time when the command was issued cdr error c lake zap The following command deletes all errors from the error table that occurred at or before 2 56 in the afternoon on May 1 1998 cdr error p 1998 05 01 14 56 00 The following command deletes all errors from the error table that occurred at or after noon on May 1 1998 and before or at 2 56 in the afternoon on May 1 1998 cdr error p 1998 05 01 14 56 00 1998 05 01 12 00 00 The following command moves the error table to dbspacel on all defined servers cdr error a m dbspacel 11 46 Guide to Informix Enterprise Replication cdr list group cdr list group The cdr list group command displays information about the groups on the current server Syntax cdr list group p 11 8 Usage The cdr list group command displays information about
50. conflict C optimize O scope S Meaning Specifies the rule that will be used for conflict resolution When a conflict occurs and the row to be replicated meets the following conditions the replicated row is accepted and the stored procedure is not called m The row is from the same database server that last updated the local row on the target table m The row has a time stamp greater than or equal to the local row When this option is not present the stored procedure defined for the replicate is always called when conflict is detected Specifies the scope for conflict resolution If scope is not specified the default scope is transaction When specifying the scope you can abbreviate trans action to fewer letters Command Line Utility 11 29 car define replicate Special Options Special Options Back to cdr define replicate p 11 27 J following table shows ats ris floatcanon firetrigger sequential parallel The special options for cdr define replicate have the meanings that the floatcanon F 11 30 Guide to Informix Enterprise Replication Options Long Form Short Form Meaning ats A Activate aborted transaction spooling for replicate transactions that fail to be applied to the target database For more information see Chapter 10 Diagnosing Enterprise Replication ris R Activates row information spooling for replicate row data that fail
51. data structure in which the parent is one step closer to the root than the child A database server that has a limited catalog and no descendants A root server is fully connected to all other root servers It has information about all other replication servers in its replication environment Figure 2 2 on page 2 5 shows an environment with four root servers A nonroot server is similar to a root server except that it forwards all replicated messages for other root servers and their children through its parent All nonroot servers are known to all root and other nonroot servers A nonroot server can be a terminal point in a tree or it can be the parent for other servers All root and nonroot servers are aware of all other servers in the replication Replication Topology Types A leaf server is a server with a sparse catalog A leaf server has knowledge only of itself and its parent server A leaf server is a terminal point in a tree it cannot be a parent to another replication server Replication Topology Types The topology that you choose influences the types of replication that you can use The next sections describe the topologies that Enterprise Replication supports Fully Connected Fully connected replication topology indicates that all database servers connect to each other and that Enterprise Replication establishes and manages the connections Replication messages are sent directly from one database server to another N
52. data if the data is found to be undeliverable as the following table shows Function Sets the replicated column to null Retains the local data This is the default Aborts the row Aborts the transaction Distributing BYTE and TEXT Data If Enterprise Replication processes a row and discovers undeliverable BYTE or TEXT columns the following actions can occur Set any undeliverable columns to null if the replication operation is an INSERT and the row does not already exist at the target Retain the old value of the local row if the replication operation is an UPDATE or if the row already exists on the target 5 14 Guide to Informix Enterprise Replication GLS Replicating User Defined Data Types Replicating User Defined Data Types Enterprise Replication supports all built in Informix data types across heter ogeneous platforms The following restrictions apply to user defined types UDTs in the SELECT statement of the participant modifier m The primary key cannot be a UDT m The replication must be between homogeneous platforms m The WHERE clause of the participant modifier cannot contain user defined types m The data for multirepresentational UDTs complex and collection types must be stored in the row Because the user has no control over when such data moves from the row into a smart large object Informix recommends that you avoid multirepresentational UDTs Replicating Smart Large Objects This ve
53. defined the database servers usa italy and japan as replication servers You can use these replication servers if you do not want to redefine the replication servers with ERM To continue without redefining the replication servers 1 Start ERM For information about starting ERM refer to Primary Target Example Using ERM on page 3 16 2 Select the g_usa replication server from the server dialog box 3 Skip to Creating the Primary Target Replicate on page 3 26 Tip If you continue without redefining the replication servers the displays in ERM will include repl1 and repl2 Defining the First Replication Server Before you replicate data you must define the database servers as replication servers A replication server is a database server that has an extra database syscdr that holds replication information Important This section assumes that you have not yet defined any replication servers When you open the Replication Manager it checks to see whether you defined any database servers for Enterprise Replication If you defined at least one replication server the Replication Manager main window appears 3 18 Guide to Informix Enterprise Replication Defining the First Replication Server If you did not define any replication servers that is if you are starting repli cation for the first time you must define a database server for replication before you can continue ERM display
54. error definition of 7 12 Replication server See Database server Replication system primary target 4 3 update anywhere 4 9 Replication volume analyzing for capacity 5 10 Resume data delivery for a replicate 12 36 for replicate group 12 35 to a server 12 37 Return codes description 11 13 list of C 1 RIS See Row information spooling rofferr utility Intro 14 Row by row conflict resolution scope 2 16 7 14 Row information spooling RIS activate 11 30 11 36 11 56 deactivate 11 56 12 26 definition of 7 20 directory 11 35 11 59 field in structure 12 7 sample output 10 12 syntax 10 9 S Safely stored definition of 7 11 Sample code conventions Intro 12 Scripting view 8 39 SELECT statement in syscdrpart B 9 limitations 2 12 11 11 12 16 performance 5 10 with shadow columns 6 4 Semi stable queue definition B 14 Send queue dbspace 12 19 definition of 7 11 location 11 35 11 36 planning space for 5 6 SERIAL data type 4 10 J K L MN OP QRS TU VW X Y Z Serial keys defining in update anywhere 4 9 Server group See Database server group setup program and sqlhosts registry E 1 Severe error table See Error table Shadow column information in ATS file 10 6 resolving collisions 7 19 Shadow columns creating 6 4 with BEGIN WORK WITHOUT REPLICATION 6 6 with DB Access 6 10 with HPL 6 4 with UNLOAD 6 6 Simple large objects 5 11 Software dependencies Intro 4 Spooling directories planning for ca
55. from the send queues for the specified database server The command shuts down Enterprise Replication on the database server and removes the global catalog from the database server When you delete an Enterprise Replication server you must issue the cdr delete server command twice The first cdr delete server removes the Enter prise Replication server from the local global catalog and removes the Enterprise Replication connection to other hosts The second cdr delete server removes the Enterprise Replication server from the replication server that you want to delete You can issue the delete server command from any replication server The only limitation is that one cannot delete a server with children You must delete the children of a server before deleting the parent server 11 40 Guide to Informix Enterprise Replication cdr delete server Examples This example removes the server g_italy from the replication environment Assume that you issue the commands from the replication server g_usa cdr delete server g_italy cdr delete server c italy g_italy The first command cdr delete server g_italy performs the following actions Removes g_italy from the usa global catalog Drops the connection from g_usa to g_italy Removes g_italy from all participating replicates Purges the replication data destined for g_italy from send queues Broadcasts this delete server command to all other servers other than g_italy so that they
56. g_boston 3 cdr define server c denver I N ats ix myats 4 S g_usa g_denver 5 cdr list server 6 cdr list server connect denver 7 cdr define server c miami I leaf S g_boston g_miami 8 cdr list server c miami 9 cdr list server g_usa Lines 1 and 2 Lines 1 and 2 add boston to the replication hierarchy as a nonroot server attached to the root server usa The backslash at the end of line 1 indicates that the command continues on the next line Lines 3 and 4 Lines 3 and 4 add denver to the replication hierarchy as a nonroot server attached to the root server usa This command uses short forms for the connect init and sync options For information about the short forms refer to Option Abbreviations on page 11 6 The command also specifies a directory for collecting information about failed replication transactions ix myats 3 14 Guide to Informix Enterprise Replication Defining a Hierarchy Line 5 Line 5 lists the replication servers as seen by the usa replication server The root server usa is fully connected to all the other root servers Therefore usa knows the connection status of all other root servers and of its two child servers denver and boston The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_boston 3 Active Connected Augl9 14 20 03 1999 g_denver 27 Active Connected Augl9 14 20 03 1999 g_italy 8 Active Connected Augl9 14 20 03 1999 g_jap
57. gt Start Replication When you start Enterprise Replication for a database server the global catalog tables are reread and all necessary Enterprise Replication threads restarted If the database server from which you are starting Enterprise Replication is the primary database server Enterprise Replication restarts the evaluation of the data marked for replication in the logical log Database server connections are either accepted or created as required based on information in the global catalog The start command is only effective after a Stop Replication command is issued To start a replicate using CLU refer to cdr start replicate on page 11 67 Specifying Privileges The Server gt Use Table Owner and Server gt Use Informix menu items let you specify how permission checks should be applied to replication opera tions Server gt Use Table Owner causes permission checks for owner to be applied to the operation such as insert or update that is to be replicated and to all actions fired by any triggers Server gt Use Informix causes all opera tions to be performed with the privileges of user informix The default is to use the privileges of user informix Enterprise Replication Menus 8 29 Removing a Database Server from Enterprise Replication To specify the permission checks using CLU refer to cdr define replicate on page 11 27 Removing a Database Server from Enterprise Replication gt Important Ifyou remove a da
58. in the catalog 0x0001 Peer request failed definition persists 0x0002 Inactive state 0x0004 Active state 0x0008 Database server is suspended 0x00010 Marked for deletion and waiting for cleanup to occur 0x00020 Temporary state in transition The syscdrspart table contains participant information B 8 Guide to Informix Enterprise Replication Column Type Description repIname char 128 Replicate name servername char 128 Database server name partstate char 18 Participant state ACTIVE INACTIVE partmode char 1 P primary database server read write R target database server read only usetabowner integer Use table owner to derive permissions 1 enabled 0 not enabled dbsname char 128 Database name 1 of 2 Column owner tabname selectstmnt syscdrprog Type char 32 char 128 text syscdrprog Description Owner name Table name SELECT statement for this participant 2 of 2 The syscdrprog table lists the contents of the Enterprise Replication progress tables The progress tables keep track of what data has been sent to which servers and which servers have acknowledged receipt of what data Enter prise Replication uses the transaction keys and stamps to keep track of this information The progress table is two dimensional For each server to which Enterprise Replication sends data the progress tables keep progress information ona per replicate basis Column dest_id g
59. of hours and minutes To specify hours and minutes give the number of hours followed by a colon and then the number of minutes For example e 5 45 indicates 5 hours and 45 minutes between replications Example Using the Command Line Utility This section contains a simple example of replication that uses the CLU Prepare the Environment To run this replication example you need two Informix database servers Each database server must be in a separate database server group You can run two database server instances on one computer but it is more realistic to use database servers on different computers The example uses the following environment Two computers are hosts for the database servers urban and rural All commands in this example except for creation of the sample database lake_db are issued by a person working on urban m The database servers are named hill and lake m The database servers hill and lake are members of the database server groups g_hill and g_lake respectively 11 16 Guide to Informix Enterprise Replication Declare the Database Servers for Replication The databases for this example are identical stores_demo databases with logging On the hill host urban create the hill_db database urban gt dbaccessdemo hill_db 10g On the lake host rural create the lake_db database rural gt dbaccessdemo lake_db log Declare the Database Servers for Replication Before replicating data y
60. p 11 8 Element Purpose Restrictions Syntax server_group Name of the server group to The server group must be Database Server disconnect currently active in Enterprise Group p 11 12 Replication Usage The cdr disconnect server command drops the connection between server_group list and the server specified in the Connect option If the Connect option is omitted the command drops the connection between server_group and the default database server INFORMIXSERVER Example The following example drops the connection between the default database server INFORMIXSERVER and the server group g_storel cdr disconnect server g_storel Command Line Utility 11 43 cdr error cdr error The cdr error command manages the error table and provides convenient displays of errors Syntax cdr error p 11 8 a Connect Option J seq err_server seqno first 3 NK prune Koo zap A move dbspace_ name all follow all nomark Element Purpose Restrictions Syntax dbspace_name The dbspace where the error The dbspace must exist Identifiers p 8 8 table is stored err_server Name of database server group The server must be registered for Identifiers p 8 8 that holds the error table Enterprise Replication Start date for a range Must be a valid date and time Time of Day p 11 15 Ending date for range Must be a later date and time Time of Day p 11 15 than first Sequence num
61. read write capabilities to allow peer to peer replication Enterprise Replication Manager Wizards 9 9 Specifying Identical or Non Identical Participants Specifying Identical or Non Identical Participants After you select the database servers that will participate in the replicate the Define Replicate wizard asks whether the attributes of all participants are identical The participant attributes are the table name owner of the table database in which the tables resides and the SELECT statement If the attributes are identical for all participants you will only need to specify them once If the attributes are not identical you must define each participant separately For example if user informix owns identical stores databases on all database servers in the replicate and you want to replicate the same columns on each customers table then the participant attributes are identical If on the other hand the databases in the replicate have identical columns but one database is named mansions while the other database is named villas then the attributes are not identical 9 10 Guide to Informix Enterprise Replication Specifying Identical or Non ldentical Participants Figure 9 6 shows the identical attributes query page for nonexpert mode In nonexpert mode only one participant can be the primary In expert mode several participants can be primaries as Figure 9 5 on page 9 9 illustrates Figure 9 6 Identical Attributes
62. server INFORMIXSERVER and suspends the servers g_iowa g_ ohio and g_utah cdr suspend serv g_iowa g_ohio g_utah 11 78 Guide to Informix Enterprise Replication API Functions In This Chapter oo wae ais a ls a Be RS Basic Information for APIs 123 Database Server Groups 2 a ee 123 Time Specifications 2 2 2 ee ee ee 125 Identifiers 2 2 ehe og saat a os aae ad alade 125 APT Structures oo aae g e o eee 125 Severe Error Table 2 2 0 eee 12 7 Information Maintained in the Severe Error Table 12 7 Retrieving Information from the Severe Error Table 12 8 Enterprise Replication APIs 2 2 2 2 1 we eee 128 cdr_connect 2 2 ee ee ee ee ee 12 10 cdr_define_group 2 eee 12 11 cdr_definerepl 2 2 2 ee 12 14 cdr_define_serv 2 2 ee eee ee 12 18 cdr_delete_group 2 0 ee ee ee 12 20 cdr_delete_repl 2 2 2 2 ww ee eee 12 221 cdr_delete_serv 2 2 ee ee ee ee 12 22 cdr_error_reviewed 2 2 2 2 ee eee ee 12 23 cdr_modify_group 2 12 24 cdr_modify_repl 2 2 12 28 cdr_modify_replmode 2 2 2 2 we ee 12 27 cdr_modify_serv 2 2 2 12 28 cdr_modify_servmode 2 ee 12 29 cdr_move_errortab ee ee 12 30
63. server serverB to purge the entry of the deleted server serverA from the catalog of serverB This update to the catalog of serverB is then replicated to all other replication servers 12 22 Guide to Informix Enterprise Replication cdr_error_reviewed cdr_error_reviewed The cdr_error_reviewed function marks a specified error as reviewed Syntax include cdrapi h int cdr_error_reviewed orig_server remote_seqnum char orig_server long remote_seqnum orig_server is the name of a database server group remote_seqnum is the remote sequence number value for the error that is to be updated Combined with the originating database server name remote_seqnum provides a unique key for every error Usage The cdr_error_reviewed function marks an error in the severe error table as having been reviewed The orig_server specifies the database server group that includes the database server where the error originated When an error is reviewed it means that someone has resolved the reason for a given error The review state is used only to track and determine which errors to delete with cdr_prune_errors The originating database server name and the sequence number from that database server are used to uniquely specify the error to be marked The specified error is updated on all database servers participating in replication API Functions 12 23 cdr_modify_group cdr_modify_group The cdr_modify_group
64. server name for all references to database servers Informix database servers allow you to create a database server group that includes several database server aliases Database server groups are useful for example if multiple connection protocols are available for connecting to a single database server In practice a database server group usually contains only one database server name If you use both DBSERVERNAME and DBSERVERALIASES DBSERVERNAME should refer to the network connection and not to a shared memory connection For information about database server aliases refer to the Administrator s Guide for Informix Dynamic Server 2000 API Functions 12 3 Database Server Groups UNIX WIN NT On UNIX the sqlhosts file defines database server groups The first line in the following example specifies a database server group The second line specifies a database server that belongs to the group g_svrA group s 1 92 svrA ontlitcp smoke svcname g g_srvA With Dynamic Server Version 7 31 use the IECC Add Database Servers wizard to prepare the SQLHOSTS connectivity information With Dynamic Server Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction for information about preparing the SQLHOSTS connectivity information This manual uses the convention that the name of a database server group is g_ followed by the name of a data
65. start replicate on page 11 67 Enterprise Replication Menus 8 15 Changing Replicate States Inactive When a replicate is in inactive state no database changes are captured trans mitted or processed When you first define a replicate it is inactive To change the state of a replicate to inactive select the replicate and then choose Replicate gt Stop Replicate The right hand display in Figure 8 5 shows a Stop Replicate dialog box If you select a participant the Replicate menu changes to include Stop Participant instead of Stop Replicate When you choose Stop Participant only the single participant that you selected becomes inactive To stop a replicate or a participant with the CLU refer to cdr stop replicate on page 11 71 Quiescent If you choose Replicate gt Stop Replicate or Stop Participant the replicate or participant enters a quiescent state No more database changes are captured for the replicate or participant However activity continues until all changes on transactions that are already committed are delivered Only complete transactions are delivered None of the changes from a transaction that is committed after Stop Replicate or Stop Participant are delivered The quiescent state is a temporary state You cannot control the quiescent state from the Replication Manager Suspended In suspended state the replicate still captures and accumulates database changes but does not transmit any of
66. structure refer to API Structures on page 12 5 Attributes Defined cdr_define_repl and cdr_modify_repl You can use the following attributes with both cdr_define_repl and cdr_modify_repl For a description of these attributes see cdr_define_repl on page 12 14 A_ATS A_BEGIN A_CANONICAL A_FREQ A_PRIMARY A_RIS A_RSCOPE A_SECONDARY API Functions 12 25 cdr_modify_repl m A TRIGGER m A_TSCOPE m A_USETABOWNER You cannot modify the ignore conflict rule to timestamp or stored procedure nor can you modify timestamp or stored procedure to ignore However you can use A_PRIMARY and A_SECONDARY to modify the conflict resolution rule from timestamp to stored procedure and back again Additional Attribute Values for cdr_modify_repl In addition to the attributes specified in cdr_define_repl0 you can use the following attribute values with cdr_modify_repl Type of Value Value of flags Field Description Transaction A_NRIS Deactivate row information spooling for this replicate spooling Transaction A_NATS Deactivate aborted transaction spooling for this spooling replicate Triggers A_NTRIGGER Triggers should not be fired for this replicate Frequency A_FREO Modifies the frequency according to the frequency in the attributes 12 26 Guide to Informix Enterprise Replication cdr_modify_reolmode cdr_modify_replmode The cdr_modify_replmode function changes the mode of partic
67. syscdrgrp B 7 syscdrgrppart B 8 syscdrpart B 8 syscdrprog B 9 syscdrq B 10 syscdrqueued B 11 syscdrrecv_buf B 11 Index 5 A BC DEFGH syscdrrecv_txn B 11 syscdrrepl B 12 syscdrs B 13 syscdrsend_buf B 14 syscdrsend_txn B 15 syscdrserver B 15 syscdrtx B 17 syscdrtxproc B 17 T Terms aborted transaction spooling ATS 7 20 row information spooling RIS 7 20 TEXT data distributing 5 14 Threads list of 5 8 used by Enterprise Replication 5 8 Time synchronization 5 9 Time evaluating 7 4 Time stamp conflict resolution rule definition of 7 15 evaluating blob data 5 12 synchronize clocks 7 16 Tip icons Intro 9 Transaction conflict resolution scope 2 16 7 14 constraint checking 7 14 evaluation examples 7 7 7 10 evaluation logic 7 6 processing impact of 5 10 Trigger based data capture 1 6 transaction capture 1 6 Triggers activate firing 11 31 11 56 11 57 deactivate firing 11 56 12 26 implementation of 7 21 in multiple row images 7 10 in primary key updates 7 10 permissions on 11 10 6 Guide to informix Enterprise Replication JKLMNOPQRSTUVV xv ze U UDTs 5 15 UNIX operating system default locale for Intro 5 Update anywhere replication system 4 9 User defined data types 5 15 V Version number 8 37 Volume analyzing replication volume 5 10 W Warning icons Intro 9 Windows NT default locale for Intro 5 Wizard define replicate 9 4 define replicate group 9 15 generic configuration 9 17
68. systems allow peer to peer updates and therefore require conflict detection or conflict resolution rules Adminis tration of this type of replication system requires more administrative steps than the previously mentioned replication systems Delivering Consistent Information Some risk is associated with delivering consistent information in an update anywhere replication system You determine the amount of risk based on the type of conflict resolution rules and procedures you choose with which to resolve conflicts You can configure an update anywhere replication system where no data is ever lost however you might find that other factors for example performance outweigh your need for a fail safe mechanism to deliver consistent information Planning for Capacity All replication systems require you to plan for capacity changes For more information see Chapter 5 Setting Up Your Replication Environment Planning for High Availability High availability is a key element in the update anywhere replication system Because all database servers have read write capabilities you can easily remove or add database servers from the replication system Select an update anywhere replication system if your business requires a fail safe system 4 10 Guide to Informix Enterprise Replication Setting Up Your Replication Environment In This Chapter Operational Limitations SOL Statement Use Forbidden SOL Statements Li
69. that mode Figure 9 1 Modifying a Generic Replicate 9 4 Guide to Informix Enterprise Replication Choosing a Conflict Resolution Procedure Choosing a Conflict Resolution Procedure If you are defining a primary target replicate the wizard goes directly to Choosing Replicate Options on page 9 6 However for update anywhere replication you must choose a conflict resolution procedure Figure 9 2 shows Timestamp and Stored Procedure conflict resolution When you specify a stored procedure in the wizard you must have already written and registered the stored procedure You cannot enter a procedure name and then create the procedure later For information about creating stored proce dures refer to the Informix Guide to SQL Syntax Figure 9 2 Timestamp and Stored Procedure Conflict Resolution Define Replicate Wizard TimeStamp and Stored Procedure aProcedure The option to optimize the stored procedure is grayed out in Figure 9 2 because you can optimize the stored procedure only when you use the procedure without the timestamp For more information about conflict resolution refer to Choosing Conflict Resolution Rules and Scopes on page 7 13 Enterprise Replication Manager Wizards 9 5 Choosing Replicate Options Choosing Replicate Options The wizard next asks you to set options for the new replicate Figure 9 3 shows the default options For more information about the options refer to Vi
70. that updates tables X and Y will be split if replication for table X is suspended Command Line Utility 11 75 Syntax Example The following example connects to the database server stan and suspends the replicate house cdr sus repl connect stan house 11 76 Guide to Informix Enterprise Replication cdr suspend server cdr suspend server cdr suspend server The cdr suspend server command suspends the delivery of replication data to a database server Syntax Connect Option server_ group p 11 8 Element Purpose Restrictions Syntax server_group Name of server group to suspend The server group must be Database Server currently active in Enterprise Group p 11 12 Replication Usage The cdr suspend server command suspends delivery of replication data from the current database server specified to the database servers included in the server_group list The current database server is server specified in the Connect option or the default server INFORMIXSERVER The connection to the suspended server is unaffected and control and acknowledge messages continue to be sent to that server Replication data continues to all other database servers If the server_group list is omitted the command suspends replication of data to all database servers participating in the Enterprise Replication system Command Line Utility 11 77 cdr suspend server Example The following example connects to the default
71. the captured data The data is queued and waits until the state is changed to active to transfer the captured data You cannot suspend a replicate unless at least one of its participants is active To change the state to suspended choose Replicate gt Suspend Replicate To change a replicate from suspended state back to its previous state choose Replicate gt Resume Replicate The database server transfers all data accumulated during the suspended state After all the data is transferred the replicate returns to active state 8 16 Guide to Informix Enterprise Replication Changing the Primary Participant Warning When a group is suspended Enterprise Replication holds the replication data in the send queue until the group is resumed If lots of data is generated for the group while it is suspended the send queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize transactions if a replicate is suspended For example a transaction that updates tables X and Y will be split if replication for table X is suspended To suspend a replicate with the CLU refer to cdr suspend replicate on page 11 75 To resume a replicate with the CLU refer to cdr resume replicate on page 11 62 Changing the Primary Participant Important This option is available only in expert mode One of the participants in a replicate is the primary database server Changes on the primar
72. the entry in the Spooling directory box to tmp Remember the usa database server is on a UNIX computer m Leave the other values set to the defaults For information about the Queue dbspaces refer to Receiving and Sending Data from the Message Queue on page 7 11 m Click OK to continue Replication Examples 3 21 Defining the First Replication Server The Declare Server Dialog Box for Expert Mode If you are in expert mode follow these steps to declare the usa replication server Leave the default choice Root Server in the Server Type box Remove the check mark from Use a Synchronization Server in the Synchronization Server box m Leave the other values set to the defaults When you finish the dialog box should look like F m Click OK to continue Figure 3 6 Declare Server Dialog Box for Expert Mode Declare Server Rootsevet OOOO SSyHChhOniedl Ott SERVer 3 22 Guide to Informix Enterprise Replication Defining the First Replication Server Choosing Nonexpert Mode The rest of this example assumes that you are in nonexpert mode If you are in expert mode the instructions and the figures will not match your display When the main ERM window reappears select Window gt Expert Mode to remove the check beside Expert If there is no check as in Figure 3 7 you are already in nonexpert mode Figure 3 7 Window Menu Expert Mode Displaying the List of Servers To display the list of
73. the update into an insert and sends it to the target For a detailed example that illustrates the evaluation of data in a single transaction where one row is inserted and then updated several times see Evaluating Images in a Complex Transaction on page D 1 7 10 Guide to Informix Enterprise Replication Receiving and Sending Data from the Message Queue Enterprise Replication supports the replication of BYTE and TEXT data Enterprise Replication implements the replication of BYTE and TEXT data somewhat differently from the replication of other data types Read through these sections to understand the processes used to evaluate data for repli cation and then read Replicating Simple Large Objects on page 5 11 Receiving and Sending Data from the Message Queue Enterprise Replication uses receive and send queues also referred to as the message queues to receive and deliver replication messages to and from database servers that participate in a replicate m Receive queue A dbspace that holds replication messages at the target database server until the target database server acknowledges receipt of the messages The pathname that specifies the receive queue dbspace can be no longer than 256 bytes For more information see Chapter 5 Setting Up Your Replication Environment m Send queue A dbspace that stores replication messages to be delivered to target database servers that participate in a replicate The path
74. this row data in hexadecimal format Aborted transaction spooling only occurs if the entire transaction is aborted Transactions defined with row scope that have aborted rows but are success fully committed on the target tables are not logged All rows that fail conflict resolution and have row scope are also written to the Preparing to Use ATS The following output is an example of an ATS file for a transaction sent by server sls4 to server pur1 The file is named ats purl sls4 D_2 960529 23 27 16 6 The file contents are TXH RIS file tmp plsl ris purl sls4 D_2 960529_ 23 27 16 5 has also been created for this transaction TXH Source 1D 390 Name s1s4 CommitTime 96 05 29 23 26 24 TXH Target 1D 392 Name purl ReceiveTime 96 05 29 23 27 16 TXH Number of rows processed when transaction was aborted 4 TXH All rows in a transaction defined with row scope were rejected RRH Row 1 Group Id 24707077 Replicate Id 24707077 Table stores cdr item DbOp Update RRS 390 s1s4 833437578 96 05 29 23 26 18 RRD 20 VGA Card 439 A Acer Chevrolet VGA Card 439 422 00 538 00 738 00 13 00 12 00 8 00 Normal Demand Moderate Value Item RRH Row 2 Group Id 24707077 Replicate Id 24707077 Table stores cdr item DbOp Update RRS 390 s1s4 833437580 96 05 29 23 26 20 RRD 10 Digitizer 319 A Apple Toyota Digitizer 319 29 00 36 00 581 00 28 0 0 2 00 2 00 Normal Demand Moderate Value I
75. to Enterprise Replication and thus create the syscdr database on the database server lake while working on the urban computer The sync option instructs the command to use the already defined server g_hill as a pattern for the new definition 5 Verify that the second definition succeeded You can use one of the following actions m Use the CLU option cdr list server m Use DB Access to check the Enterprise Replication servers in the sysmaster database The following two statements should show the same results SELECT servid servname FROM sysmaster hill syscdrs SELECT servid servname FROM sysmaster lake syscdrs Define Replicates The replicate definition has four basic parts options the replicate name and two participants 1 Define a replicate that records all changes to the customer table urban cdr define repl C ignore repli A hill_db g_hill informix customer A select from customer lake_db g_lake informix customer A select from customer 2 Verify that the definition succeeded You can use one of the following actions m Use the CLU option cdr list replicate m Use DB Access to check the replicate definitions SELECT replname replstate FROM sysmaster syscerrepl 11 18 Guide to Informix Enterprise Replication Start Replication Start Replication You have now described the replication environment but no replication occurs until you instruct Enterprise Replication to start replicating
76. transfer overhead An efficient log based transaction capture mechanism is an integral part of the database system To replicate data throughout an open systems enterprise is much more complex than to copy data from one database server to another In many situations the most efficient and cost effective data replication is an asynchronous replication that uses a log based transaction capture mechanism Informix Enterprise Replication Features Many data replication products use the following key elements to success fully replicate data throughout an open system enterprise High performance High availability Consistent information delivery Flexible architecture Easy centralized administration This section associates the key elements of data replication with Enterprise Replication features 1 8 Guide to Informix Enterprise Replication High Performance High Performance A replication system must not overly burden the source of the data must use networks efficiently and must use all resources efficiently Enterprise Replication uses a log based transaction capture mechanism that is integrated in the database architecture The database server can implement this capture mechanism efficiently because the capture mechanism is internal to the database In addition all replication operations are performed in parallel which further extends the performance of Enterprise Replication Enterprise Replication operates in a
77. which the replication should be stopped time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage The cdr_stop_repl function causes replicate rep to enter the inactive state no data capture no send on the database servers in the servers list If the servers list is null then replication stops for all database servers If rep is contained in a replicate group the call fails To stop data transmittal for a replicate group see cdr_stop_group on page 12 42 API Functions 12 43 cdr_suspend_group cdr_suspend_group The cdr_suspend_group function suspends delivery of replication data for replicates contained in a replicate group Syntax include cdrapi h int cdr_suspend_group group time char group time_t time not used group is the replicate group name time is not used but cannot be omitted Use time_t 0 for that argument Usage The cdr_suspend_group function causes the replicates contained in the replicate group group to enter the suspend state that is do not capture or send replication data for all participants Warning When a group is suspended Enterprise Replication holds the replication data in the send queue until the group is resumed If lots of data is generated for the group while it is suspended the s
78. 0 8 30 Guide to Informix Enterprise Replication Reloading the Global Catalog Reloading the Global Catalog To reload the global catalog for a database server select the database server and choose Server gt Reload from Global Catalog Reloading the global catalog ensures that ERM is using up to date information about the database server Viewing Database Server Properties To view database server properties choose Server gt Server Properties to access the Server Properties dialog box The Server Properties dialog boxes in sure 8 11 summarizes the properties you have assigned to a database server s n Figure 8 11 Server Properties Server Properties Dialog Boxes Expert Mode and Nonexpert Mode Server Properties Enterprise Replication Menus 8 31 View Menu Click the General tab to show the replication server name and for expert mode the idle time out The Queue dbspace tab shows the location of the Send and Receive queues The Spooling Directories table lets you change the locations of the ATS and RIS directories In expert mode the Routing tab gives information about the position of the replication server in the replication hierarchy View Menu The View menu lets you choose how information is displayed The View menu has the following options By Replicate By Server Toolbar Status Bar By Replicate and By Server Use the View menu to view information by database server or by rep
79. 12 29 12 30 12 31 12 32 12 33 12 34 12 35 12 36 Table of Contents xi Section IV Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F cdr_resume_serv cdr_start_cdr cdr_start_group cdr_start_repl cdr_stop_cdr cdr_stop_group cdr_stop_repl cdr_suspend_group cdr_suspend_repl cdr_suspend_serv Example Appendixes Configuration Parameters SMI Tables for Enterprise Replication Return Codes Fine Tuning Enterprise Replication SQLHOSTS Registry Key Enterprise Replication onstat g Options xii Guide to Informix Enterprise Replication 12 37 12 38 12 39 12 40 12 41 12 42 12 43 12 44 12 45 12 46 12 47 Introduction In This Introduction About This Manual Types of Users Software Dependencies Using Enterprise Replication Manager Assumptions About Your Locale Demonstration Databases New Features 7 Extensibility Enhancements Performance Improvements Special Features Documentation Conventions Typographical Conventions Icon Conventions Comment Icons Feature Product and Platform ON Command Line Conventions How to Read a Command Line De Sample Code Conventions Additional Documentation On Line Manuals Printed Manuals On Line Help i Error Message Documentation Documentation Notes Release Notes Machine Notes Related Reading NON 00 DADO JI JIA A RW Q Compliance with Industry Standards Infor
80. 2 Line 9 gives the participant and participant modifier that should be added Line 10 Line 10 gives detailed information about repl2 After the addition of the participant in lines 8 and 9 the command returns the following information REPLICATE SERVER STATE TABLE SELECT repl2 g_usa INACTIVE manufact select from stock repl2 g_italy INACTIVE manufact select from stock repl2 g_japan INACTIVE manufact select from stock Replication Examples 3 11 Cause a Replication Line 11 The display for line 10 shows that the STATE of rep12 is INACTIVE Line 11 makes the replicate active Changes made to the stock table on usa are reflected in the stock tables on both italy and japan Line 12 Line 12 displays a list of replicates so that you can verify that the STATE of repl2 has changed to ACTIVE The command returns the following information REPLICATE STATE CONFLICT FREQUENCY OPTIONS repll ACTIVE ignore immediate row repl2 ACTIVE ignore immediate row Cause a Replication Now you can modify the stock table on one database server and see the change reflected on the other database servers Changing the stock Table on the usa Database Server Use DB Access to insert a line into the stock table on usa INSERT INTO stores usa stock VALUES 401 PRC ski boots 200 00 pair pair Observe the change on the italy and japan database servers SELECT from stores italy stock SELECT from stores japan st
81. 2 evaluator threads per CPU VP For a3 CPU VP server 3 2 6 2 evaluator threads per CPU VP For a 3 CPU VP server 3 2 0 6 4 evaluator threads for any database For a3 CPU VP server 3 0 4 4 server Configuration Parameters A 3 CDR_LOGDELTA CDR_LOGDELTA default value 30 range of values 0 to 100 takes effect when Enterprise Replication is initialized The CDR_LOGDELTA configuration parameter specifies the percent of the space reserved for logical logs that can be devoted to memory for the send and receive queues If the evaluation of transactions for replication is much slower than the actual rate of transactions the evaluation can fall considerably behind In that case Enterprise Replication blocks out further transactions to let the transaction evaluation catch up If your log size is small you can increase CDR_LOGDELTA to prevent the database server from overcommitting queue memory during this catch up phase You can also use CDR_QUEUEMEM to limit the memory that the database server uses for the send and receive queues The database server uses the lower of the values derived from CDR_QUEUEMEM and CDR_LOGDELTA For information about CDR_QUEUEMEM refer to CDR_QUEUEMEM on page A 7 A 4 Guide to Informix Enterprise Replication CDR_NIFCOMPRESS CDR_NIFCOM PRESS default value 0 range of values 1 donot compress 0 compress only if the target server expects compression 1 9 increasing levels of c
82. 31 Q Queue receive definition of 7 11 send definition of 7 11 See also Receive queue See also Send queue Quiescent state replicate definition of 8 16 8 23 R Receive queue dbspace 12 19 definition of 7 11 field in structure 12 7 location 11 35 11 36 planning space for 5 6 JK L MN OP QRS TU VW X Y ze regedt32 program and sqlhosts registry E 3 Related reading Intro 16 Release notes Intro 15 Replicate aborted transaction spooling 11 30 adding participants 11 22 12 32 adding to group 11 20 attributes modify 12 25 change participant mode 12 27 conflict options 11 28 creating 11 27 12 14 definition of 2 9 deleting 11 39 12 21 deleting from group 11 20 deleting participants 11 22 listing 11 48 modify attributes 11 55 removing participants 12 32 resume data delivery 11 62 row information spooling 11 30 start data capture 11 67 stop data capture 11 71 stop data delivery 12 43 suspend data delivery 11 75 12 45 Replicate group adding replicates 8 21 changing the state 8 22 11 61 creating 8 20 11 25 12 11 definition of 2 12 deleting 8 21 11 38 12 20 listing 11 47 modify 11 53 modify attributes 12 24 performance 2 12 removing replicates 8 21 resume data delivery 11 61 start data capture 11 66 stop data capture 11 70 suspend data delivery 11 73 12 44 Replicate states how to change 8 14 Replication Event Monitor 8 11 10 14 Replication Manager toolbar icons 8 10 A BC DEFGH Replication order
83. 6 RIS directory spooling name 2 of 2 syscdrsync_buf The syscdrsync_buf table contains buffers that give information about the synchronization queue Enterprise Replication uses this queue only when defining a replication server and synchronizing it with another replication server For information on the columns of the syscdrsync_buf table refer to Columns of the Buffer Tables on page B 4 syscdrsync_txn The syscdrprog table contains information about the synchronization queue This queue is currently used only when defining a replication server and synchronizing it with another replication server The synchronization queue is an in memory only queue For information on the columns of the syscdrsync_txn table refer to Columns of the Transaction Tables on page B 3 B 16 Guide to Informix Enterprise Replication syscdrtx syscartx The syscdrtx table contains information about Enterprise Replication transactions Column srvid srvname txprocssd txcmmtd txabrtd rowscmmtd rowsabrtd txbadcnt syscdrtxproc Type integer char 128 integer integer integer integer integer integer Description Server ID Name of database server from which data is received Transaction processed from database server srvname Transaction committed from database server sruname Transaction aborted from database server sruname Rows committed from database server sruname Rows aborted from database server
84. ADS configuration parameter A 3 CDR_LOGDELTA configuration parameter A 4 CDR_NIFCOMPRESS configuration parameter A 5 CDR_NIFRETRY configuration parameter A 7 CDR_QUEUEMEM configuration parameter A 7 Central registry sqlhosts E 2 Clock synchronize time on 7 16 CLU See Command line utility Code set ISO 8859 1 Intro 5 Code sample conventions for Intro 12 Codeset conversion files 5 16 Collision definition of 7 12 Column mapping definition of 9 13 procedure D 5 Command line conventions elements of Intro 10 example diagram Intro 12 how to read Intro 12 Command line utility abbreviations 11 6 backslash 11 8 cdr change group 11 20 cdr change replicate 11 22 cdr connect server 11 24 cdr define group 11 25 cdr define replicate 11 27 cdr define server 11 33 cdr delete group 11 38 cdr delete replicate 11 38 11 39 cdr delete server 11 40 cdr disconnect server 11 43 cdr error 11 44 cdr list group 11 47 cdr list replicate 11 48 cdr list server 11 50 2 Guide to informix Enterprise Replication JK L MN O P QR cdr modify group 11 53 cdr modify replicate 11 55 cdr modify server 11 59 cdr resume group 11 61 cdr resume replicate 11 62 cdr resume server 11 63 cdr start 11 64 cdr start group 11 66 cdr start replicate 11 67 cdr stop 11 68 cdr stop group 11 70 cdr stop replicate 11 71 cdr suspend group 11 73 cdr suspend replicate 11 75 cdr suspend server 11 77 connect option 11 8 11 12 error return codes 11 13 introduction 11
85. AM 143 Don n 12 44 21 TXH Transaction committed e RRH CDR 3 Update exception row does not exist in target table converte dt srv0 395 96 05 30 08 43 39 833471019 9 10 A 234 00 0 00 0 00 0 00 Delivery in 3 days 0 00 0 00 0 00 0 0 srv3 398 96 05 30 08 43 41 833471021 Ri LRS srv4 399 96 05 30 08 43 30 833471010 RD 4 5 4 A 5 6 00 4590 00 0 00 0 00 02 04 1998 Issue from Site 2 Only By oad CusCode 15 RecQty 9 Orddty 33 0 00 0 00 0 00 0 00 4 1 3 1996 05 3 CusCode 15 RecQty 3 OrdQty 39 0 Replicate Id 25886728 Table stor wo Delivery in 3 days 0 00 0 00 0 00 3 N Replicate Id 25886737 Table stor R 0 RRS srv3 398 96 05 30 12 43 41 833471021 RRD 4 5 4 A 5 3 00 2295 00 0 00 0 00 02 06 1998 Please Issue ASAP By Roa a 2 00 0 00 0 00 0 00 4 0 5 1996 05 30 1 TXH Total number of rows in transaction 5 Diagnosing Enterprise Replication 10 13 Replication Event Monitor Messages Replication Event Monitor Messages The Replication Event Monitor displays messages in the following format Context Message The context part of Context Message includes an operation such as define server or suspend group and the name of the object of the operation The following lines show three examples of context information define replicate repl_1 start group accounts suspend server lake The message part of Context Message consists of a message that describ
86. Bo ee ee G badas a eS 8 7 Choosing Ellipses 2 2 6 ee en 8 8 Viewing Long Identifiers 2 2 2 6 6 ee ee ee ve 88 The Replication Manager Main Window 8 10 Using the Global Catalog Icon 2 2 8 10 Using the What s This Icon 2 2 2 2 ew 8 11 The e File Metiw mid ar ee ee a a oe eek eh ad pee SORE Creating Scripts ee 8 11 Monitoring Replication Events 8 11 The Replicate Menu JIS e OZ Managing Replicates and Participants Jose te Boar od al A 4 COIS Defining a Replicate 2 ee ee ee 8 13 Deleting a Replicate 2 we 8 13 Adding a Participant 8 14 Removing a Participant 8 14 Changing Replicate States 2 2 2 ww ww 8 14 Active Cie Gee oe ee we a BD Inactive 2 we ee ee ee o 8 16 Quiescent o 8 16 Suspended i owe a Hoe ok we od 2B LO Changing the Primary Participant h Boe 4 we Ais aD a SOFIA Viewing Replicate Properties General Properties Tab Conflict Resolution Tab Spooling Tab Frequency Tab Participant Properties Group Menu Defining a Replicate Group Modifying Groups Deleting a Replicate Geis Adding Replicate s to an Existing Replicate Group Removing Replicate s from an Existing plas Group Changing the State of a Group Active Inactive Quiescent Suspend i Viewing Replicate Group Properties Se
87. DSLOCKWAIT is used by Enterprise Replication while applying data at the target database This parameter is useful in conditions where different sources require locks on the replicated table These sources could be a replicated transaction from another server or a local application operating on that table Transactions that receive updates and deletes from another server in the replicate can abort because of locking problems The Datasync data synchro nization component of Enterprise Replication always does an index read on the replicated table In order to avoid deadlock the application using the table should also use index read When a database server inserts data into a table it locks the index which could potentially result in a collision with another database server A 2 Guide to Informix Enterprise Replication Number of Threads CDR_EVALTHREADS CDR_EVALTHREADS value 1 2 units evaluators range of values 1 to 129 takes effect when shared memory is initialized The CDR_EVALTHREADS configuration parameter specifies the number of grouper evaluator threads to create when Enterprise Replication starts and enables parallelism when Enterprise Replication evaluates transactions from the logical log The format is per cpu vp additional The following table provides four examples of CDR_EVALTHREADS Explanation Example 1 2 2 2 0 04 1 evaluator thread per CPU VP plus 2 For a 3 CPU VP server 3 1 2 5
88. Data Consolidation Database in a Primary Target Database server Replication System aa seve Replication 5 Read write ao Target Read write server Primar y Database we Read only server j server j Read write Read write Primary Businesses can also use data consolidation to off load OLTP data for decision support DSS analysis For example data from several OLTP systems can be replicated to a DSS system for read only analysis Pay close attention to the configuration of the tables from which data is replicated to ensure that each primary key is unique among the multiple primary database servers Selecting Enterprise Replication Systems 4 5 Workload Partitions Workload Partitions Workload partitioning gives businesses the flexibility to assign data ownership at the table partition level rather than within an application Figure 4 3 illustrates workload partitioning Asia Pacific U S A oe server server A P Partitio A P Partition pp empname gt 4402 R River U S A Partition emptt 6398 9456 E Eldridge 4951 H Height Europe Partition Europe Partition 3798 G Gladys _ Owner of partition Read write 4 6 Guide to Informix Enterprise Replication Europe a server A P Partition emp empname 5761 T 6642 Z Zachary U S A Partition 7333 K Kristen Europe Partition
89. Delete tables are stored in the same dbspaces as their base tables If the base table has 100 megabytes of data but only half the rows might be deleted or modified then 50 megabytes is a reasonable estimate for the size of the delete table Tip Delete tables are automatically deleted when the last replicate defined with conflict resolution on a table is deleted Spooling Directories The aborted transactions spooling ATS and row information spooling RIS hold information about failed transactions The default location for these directories is tmp UNIX or tmp Windows NT Informix recommends that you not leave the spooling directories in the default location but assign them to directories that you control For information about ATS and RIS refer to Chapter 10 Diagnosing Enter prise Replication Setting Up Your Replication Environment 5 7 Configuration Parameters Configuration Parameters The database server configuration file ONCONFIG includes the following configuration parameters that affect the behavior of Enterprise Replication CDR_DSLOCKWAIT CDR_EVALTHREADS CDR_LOGDELTA CDR_NIFCOMPRESS CDR_NIFRETRY CDR_NUMCONNECT CDR_QUEUEMEM These parameters are documented in Appendix A Configuration Param eters For additional information about configuration parameters refer to your Administrator s Guide Enterprise Replication Threads The following table summarizes the threads that Enterp
90. E TRIGGER DROP TRIGGER CREATE VIEW 5 4 Guide to Informix Enterprise Replication Capacity Planning DROP VIEW CREATE SYNONYM DROP SYNONYM CREATE PROCEDURE DROP PROCEDURE ADD INDEX DROP INDEX ALTER INDEX except TO CLUSTER ALTER TABLE constraints except for the primary key Important Do not create a clustered index on a table after you have defined a replicate on that table replication on the table will cease Capacity Planning The following guidelines are provided to help you plan for the additional capacity Enterprise Replication uses Logical Log Records The database server uses the logical log to store a record of changes to the data since the last archive Enterprise Replication requires the logical log to contain entire row images for updated rows including deleted rows The database server normally logs only columns that have changed This behavior is called the Logical Log Record reduction option Enterprise Replication deactivates this option for tables that participate in Enterprise Replication The Logical Log Record reduction option remains enabled for tables that do not participate in Enterprise Replication Enterprise Replication logs all columns instead of the columns that have changed which consequently increases the size of your logical log When you determine the size of your logical log examine your data activity for normal operations and for the replication s
91. EM You can also use CDR_LOGDELTA to limit the memory that the database server uses for the send and receive queues The database server uses the lower of the values derived from CDR_QUEUEMEM and CDR_LOGDELTA For information about CDR_LOGDELTA see CDR_LOGDELTA on page A 4 The maximum memory used for queued elements on a replication server is the total number of database servers involved in replication multiplied by the value of CDR_QUEUEMEM When you increase the value of CDR_QUEUEMEM you reduce the number of elements that must be written to disk which can eliminate I O overhead Therefore if elements are frequently stored on disk increase the value of CDR_QUEUEMEM Tune the value of CDR_QUEUEMEM for the amount of memory available on your computer A 8 Guide to Informix Enterprise Replication SMI Tables for Enterprise Replication The system monitoring interface SMI tables in the sysmaster database provide information about the state of the database server Enterprise Replication uses the following SMI tables to access information about database servers declared to Enterprise Replication Table syscdrack_buf syscdrack_txn syscdrctrl_buf syscdrctrl_txn syscdrerror syscdrgrp syscdrgrppart syscdrpart syscdrprog syscdrq syscdrqueued Description Buffers for the acknowledge queue Transactions in the acknowledge queue Buffers for the control queue Transactions in the control queue Ente
92. FORMIXDIR incl esql cdrapi h Windows NT typedef struct plist char serv CDR_GL_NAMESIZE 1 server group name char dbL CDR_GL_NAMESIZE 1 database char table CDR_GL_NAMESIZE 1 table char owner CDR_GL_USERSIZE 1 owner char selectstmt CDR_GL_SELECTSIZE 1 select stmt uint4 partmode participant mode struct plist part_next next participant CDR_plist typedef struct freq uint2 hr hour 0 32767 uintl min minute 0 59 uintl type see frequency types below values uintl day uintl month CDR_freq API Functions 12 5 API Structures iHefine iHdefine iHdefine define define uintl char uintl uint4 uint4 char time_ CDR_freq freq t struct CDR_idlist frequency types FREQ_IMMED 1 REQ_INTERVAL 2 w REQ_TIME REQ_DAYOFWEEK ESS EQ_DAYOFMONTH 5 typedef struct conf method storedproc CDR_GL_SPSIZE 1 storedprocopt CDR_conf typedef struct repl_attrs flags begin threshold CDR_conf primary CDR_conf secondary CDR_repl_attrs typedef struct idlist Replica default Replica interva members Replica Replica of the s Replica day of minute e all data immediately This is the value e data at the hour and minute s specified by the hour and minut
93. Functions 12 29 cdr_move_errortab cdr_move_errortab The cdr_move_errortab function moves the error table to another dbspace Syntax include cdrapi h int cdr_move_errortab dbspace performonall char dbspace int performonall dbspace is the name of the dbspace in which the error table is to be moved performonall is the flag that indicates whether this operation should be performed on all database servers or only the database server to which the user is connected Usage The cdr_move_errortab function moves the severe error table to a new dbspace All errors that are currently stored in the table are moved to the new dbspace If the performonall flag is nonzero this operation is performed on all database servers involved in replication If the performonall flag is zero this function affects only the database server to which the user is connected For more information refer to the Severe Error Table on page 12 7 12 30 Guide to Informix Enterprise Replication cdr_participate_group cdr_participate_group The cdr_participate_group function modifies a replicate group by adding or deleting replicates Syntax include cdrapi h int cdr_participate_group group op repls which char group uintl Op CDR_idlist repls void which group is the name of the replicate group op is the operation A_ADD or A_REMOVE repls is the list of replicates which points to information if an e
94. ICT FREQUENCY OPTIONS repll ACTIVE ignore immediate row repl2 INACTIVE ignore immediate row Line 5 Although line 4 shows that repl2 exists it does not give much information about the replicate itself Line 5 shows the participants usa and italy and the participant modifiers the SELECT statements for rep12 The command returns the following information REPLICATE SERVER STATE TABLE SELECT repl2 g_usa INACTIVE manufact select from stock repl2 g_italy INACTIVE manufact select from stock 3 10 Guide to Informix Enterprise Replication Preparing for an Update Anywhere Replication Line 6 Line 6 adds the japan database server to the replication system already defined in the previous example You can use either g_usa or g italy in the sync option Enterprise Replication maintains identical information on all servers that participate in the replication system Therefore when you add the japan database server information about that server is propagated to all previ ously defined replication servers usa and italy Line 7 This line displays the replication servers so that you can verify that the definition succeeded The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_italy 8 Active Connected JUN 14 14 38 44 1999 g_japan 6 Active Connected JUN 15 9 12 27 1999 g_usa 1 Active Local Lines 8 and 9 Lines 8 and 9 together form one command Line 8 specifies an addition to repl
95. LAN WAN and combined LAN WAN configuration across a range of network transport protocols Enterprise Replication uses the standard database server communication facility to establish network connectivity among the Enterprise Replication servers involved in replication High Availability A replication system must be reliable and must not expose business opera tions to computer system failures Enterprise Replication implements asynchronous data replication Asynchronous replication ensures that network and target database server outages are tolerated Enterprise Replication also uses a delivery mechanism that stores data locally and then sends the data to the remote database server in two separate transactions Target database servers acknowledge receipt of a message when the message is safely stored A message is safely stored when it is either in a queue or in the target database In the event of a database server or network failure the local database server can continue to service the local users Data Replication Overview 1 9 Consistent Information Delivery Consistent Information Delivery A replication system must protect data integrity All Enterprise Replication transactions are stored in a reliable queue to maintain the consistency of transactions Additionally Enterprise Repli cation maintains the order of transactions when data is replicated Maintaining the consistency and order of transactions ensures that if the same
96. O Sy 2 3 Enterprise Replication Topologies LS te RE Ls Ss Nats ek ace 2 3 Topology Terminology 2 ee eee 2 4 Replication Topology Types 1 ee 2 5 Enterprise Replication Objects 2 2 6 ee 2 8 Enterprise Replication Server 2 1 wwe 2 8 Replicate y arar Bak A o gee dete A 2 9 Participant 22 et eta e ot ke Ht tk Be ee 2al2 Replicate Group 2 6 6 ee 2 12 Catalog s g tra awe E eel ok a e se 24 Replication Types ms Ee te Hl ah ah AE fe ae cas ue at ZA Primary Target Replication wi ie Ae cam et Oe eae Ee age an ZO Update Anywhere Replication 2 215 Conflict Resolution is ota age Spi Oy Hee de hd ohne EID Conflict Resolution Rules Car a aa a a 216 Resolution Scope a ee ee ee ee 2 16 Replication Data Seog cee A A eee 4 ETF Evaluating Data for Replication E Se He af Be us de eee EEL Distributing Data sr w seca d a 2 19 Applying Replicated Data 2 ww 2 19 iv Guide to Informix Enterprise Replication Chapter 3 Replication Examples In This Chapter Environment for the Replication Example Terminology Primary Target amp Uiig ne CLU Preparing for a Primary Target Replication Cause a Replication Do Not Cause a Replication Update Anywhere Example Using the CLU Preparing for an Update Anywhere Replication Cause a Replication Hierarchy Example Using the CLU Preparing f
97. OK 6 Select the new key that you just made the key with the database server name 7 Choose Edit gt Add Value 8 Inthe Add Value dialog box enter one of the fields of the sqlhosts information HOST OPTIONS PROTOCOL SERVICE in the Value Name dialog box Do not change the Data Type box Click OK 9 Inthe String Editor dialog box type the value for the field that you selected and click OK 10 Repeat steps 8 and 9 for each field of the sqlhosts information SQLHOSTS Registry Key E 3 Preparing the SOLHOSTS Connectivity Information Figure E 1 illustrates the location and contents of the SOLHOSTS registry key for the database server payroll Figure E 1 sqlhosts Information in the Windows NT Registry HKEY LOCAL MACHINE on Local Machine Description E9 ForeFront E Hummingbird E Informix Informix ORDBMS Informix Storage Manager Informix Connect ISM E ONLINE E Replication Manager ROM Setup E Spaces Snap in g_denver After you create the registry key for the database server you must make a database server group that includes the database server For more infor mation refer to Database Server Groups on page 11 12 1 With the SOLHOSTS key selected choose Edit gt Add Key 2 Inthe Add Key dialog box enter the name of the database server group in the Key Name dialog box In this manual and in Figure E 1 on page E 4 each of the names of the database server
98. SAM 0 8 399 2423745 8469 00 0 00 0 0 00 83429 00 Untouched This Customer belongs to the Nation of Kamas 8 399 2423745 0 00 0 00 0 00 0 00 83429 00 Untouched This Customer belongs to the Nation of Kamas RRH Row 4 Collection Id 24707077 stores cdr item DbOp Update 23 00 12 00 Slow Moving Moderate Va 8 00 12 00 Slow Moving Moderate Va TXH Transaction aborted TXH ATS file tmp plsl ats purl sls4 for this transaction BYTE and TEXT Information in RIS Files Replicate Id 24707077 Table RRH CDR 14 Failed conflict resolution rule SQL 0 ISAM 0 LRS purl 392 96 05 29 23 26 48 833437608 LRD 9 Keyboard 173 A ALR Datsun Keyboard 173 978 00 1399 00 912 00 23 00 ue Item RRS s154 390 96 05 29 23 26 23 833437583 RRD 9 Keyboard 173 A ALR Datsun Keyboard 173 978 00 1399 00 866 00 23 00 ue Item D_2 960529_ 23 27 16 6 has also been created The following RIS output is for a committed transaction with an aborted row and a replication order exception TXH Source 1D 398 Name srv3 CommitTime 96 05 30 08 43 41 TXH Target 1D 395 Name srv0 ReceiveTime 96 05 30 08 43 42 H Row 2 Collection Id 25886728 cdr stock DbOp Update o insert SQL 0 ISAM 0 Local Row in delete Y Pror 9 10 A 234 00 327 00 0 00 0 00 1996 05 30 08 43 35 RH RS RD 1996 05 30 08 42 13 RS RD 19 RH Row 1 Collection Id 25886737 cdr orddetail DbOp Delete H CDR 0 SQL 0 IS
99. Server 2 ee ee ee ee 11 24 cdr define group ee ee ee 11 25 cdr define replicate 2 0 1 27 cdr define server 2 a ee ee ee ee 133 cdr delete group eee ee ee 1 38 cdr delete replicate 2 we 0 0 0 0 1 89 cdr delete server 0 0 0 ee ee 11 40 cdr disconnect Server ee ee ee eee 11 43 cdPerror 208 fos Sie Ao se e AA cdr list group 2 2 2 6 ee eee ee 1 47 cdr list replicate 2 a eee ee 11 48 cdr list server 2 2 ee 11 50 cdr modify group ee ee ee 11 53 cdr modify replicate 0 0 0 1 55 cdr modify server 2 we 11 59 cdr resume group 1 61 cdr resume replicate 2 1 ee ee ee 1 62 cdrresumeserver 2 1 eee ee eee ee 11 63 Cdr start lt 8 onpa Sc ee ae Se a a we te Ee Sy a 04 cdr start group 2 ee ee ee 11 66 cdr start replicate 0 0 ee 11 67 cdrstop e co e aa AE a a e ad ds 168 cdr stop group ee ee o eo 170 cdr stop replicate 0 0 0 1 71 cdr suspend group 2 ee ee 11 73 cdr suspend replicate 2 2 0 0 1 75 cdr suspend server 2 ee ee ee ee 11 77 11 2 Guide to Informix Enterprise Replication In This Chapter The command line utility CLU lets you configure and control Ente
100. T flag bit is set in mflags but the participants argument is null CDR_ENAMERR 44 Illegal name syntax CDR_plist Invalid replicate or database server name CDR_EPART 45 Invalid participant 46 not in use CDR_ESERV 47 Invalid server name CDR_ENOMEM 48 Out of memory CDR_EREPMAX 49 Maximum number of replicates exceeded CDR_EPARTMAX 50 Maximum participants CDR_ERUMOR 51 Attempt to delete server remotely CDR_ESERVUNIQ 52 Server name already in use CDR_EDUPL 53 Duplicate server or replicate CDR_EBADCRULE 54 Bad conflict rule specified CDR_ENOSCOPE 55 Resolution scope not specified CDR_ESCOLSDNE 56 Shadow columns do not exist for table Shadow columns are not present or have invalid data types If non ignore conflict resolution is chosen shadow columns must exist for replicated table 3 of 6 C 4 Guide to Informix Enterprise Replication Definition of Return Codes Numeric Mnemonic Value Description struct CDR_ECRDELTAB 57 Error creating delete table CDR_ENOCRULE 58 No conflict resolution rule specified CDR_EBADSCOLS 59 Table has bad type for shadow columns or has shadow columns at wrong place CDR_EGRPPART 60 Illegal operation on group participant CDR_ENOPERM 61 User does not have permission to issue command CDR_ENOCDR 62 Enterprise Replication not active Make sure that the INFORMIXSERVER environment variable is set to a database server that is m a member of a valid database server group m the DBSERVERNAME in the configuration
101. The size of the column if data exists for this column Blob flag CHAR 1 For the local row the field is always NULL For the replicated row m D BYTE or TEXT data is sent from the source database server m U BYTE or TEXT data is unchanged on the source database server Column type CHAR 1 P indicates tablespace data B indicates blobspace data ID of last update server CHAR 18 The ID of the database server that last updated this column for tablespace data Null for the blobspace data Last update time DATETIME YEAR TO SECOND For the tablespace data The date and time when the data was last updated For blobspace data NULL Setting Up Your Replication Environment 5 13 Replicating Simple Large Objects Value If the procedure returns an action code of A D I or U the procedure parses the return values of the replicated columns Each BYTE or TEXT column can return a two character field For information about the action codes refer to Stored Procedure Conflict Resolution Rule on page 7 17 The first character defines the desired option for the BYTE or TEXT column as the following table shows Function U Value N L Performs a time stamp check for this column as used by the time stamp rule Sets the replicate column to null Accepts the replicated data as it is received Retains the local data The second character defines the desired option for blobspace
102. Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction for information about preparing the SOLHOSTS connectivity information You can also use regedt32 to prepare SOLHOSTS information for your database servers For more information refer to Appendix E SQLHOSTS Registry Key Opening the Replication Manager When you open ERM it checks to see whether any database servers have been defined for Enterprise Replication If at least one replication server has already been defined the Replication Manager main window appears as shown in Figure 8 3 on page 8 10 8 6 Guide to Informix Enterprise Replication Understanding Server Terminology If no replication servers have been defined that is if you are starting repli cation for the first time you must define a database server for replication before you can continue Defining the First Replication Server on page 3 18 illustrates the technique for defining a replication server When you declare the first Enterprise Replication server make the following choices m Synchronization Server The first server that you declare does not have a synchronization server Make sure that the Use a Synchronization Server check box is not checked The Synchronization Server pane should be gray m Queue dbspaces If you do not want the send and receive queues to go into the root dbspace you mus
103. Without Replication The following example shows how to use DB Access to begin work without replication as well as update the Enterprise Replication shadow columns cdrserver and cdrtime DATABASE adatabase BEGIN WORK WITHOUT REPLICATION INSERT into mytable cdrserver cdrtime coll col2 VALUES 10 845484154 valuel value2 UPDATE mytable SET cdrserver 10 cdrtime 845484154 WHERE coll gt col2 COMMIT WORK Using ESQUC to Begin Work Without Replication The following example shows how to use ESQL C to begin work without replication as well as update the Enterprise Replication shadow columns cdrserver and cdrtime MAIN argc argv INT argc CHAR argvL EXE EXE SQL CHARstmt 256 SQL database mydatabase sprintf stmt BEGIN WORK WITHOUT REPLICATION EXEC SQL execute immediate stmt EXEC SQL insert into mytable cdrserver cdrtime CONT Col2s sex values 10 845494154 valuel value2 EXEC SQL update mytable set cdrserver 10 cdrtime 845494154 where coll gt col2 EXEC SQL commit work Important You must use the following syntax when you issue the BEGIN WORK WITHOUT REPLICATION statement from ESQL C programs Do not use the syntax sprintf stmt BEGIN WORK WITHOUT REPLICATION EXEC SQL execute immediate stmt 6 10 Guide to Informix Enterprise Replication Replicating Data Chapter 7 Chapter 8 C
104. XDIR bin directory on UNIX platforms and in the INFORMIXDIR bin directory in Windows environments Introduction 5 New Features New Features For a comprehensive list of new database server features see the release notes This section describes new features relevant to this manual These features fall into the following areas m Extensibility enhancements m Performance improvements m Special features Extensibility Enhancements This manual describes the following extensibility enhancements to Version 9 2 of Dynamic Server limited support of user defined and opaque data types Performance Improvements This manual describes the following performance improvements for Enter prise Replication in Version 9 2 of Dynamic Server m Improvements in managing the storage queues m Faster processing for large transactions m Better management to avoid long transactions m Improvements in the log reader Special Features This manual describes the following special features of Version 9 2 of Dynamic Server m Long identifiers o 128 character identifier o 32 character user names m Updates to the Enterprise Replication GUI and command line interface m Hierarchical routing direct connections no longer required 6 Guide to Informix Enterprise Replication Documentation Conventions Additional support and performance enhancements for database servers with intermittent connections Reduce global catalog availab
105. _attrs and CDR_plist structures refer to API Structures on page 12 5 The replicate name can be no longer than 128 bytes and must start with a letter or an underscore 12 14 Guide to Informix Enterprise Replication Type of Value cdr_define_repl Attribute Values for CDR_repl_attrs The attrs argument is a pointer to the CDR_repl_attrs structure which specifies attributes for the replicate These attributes specify how the system manages replication data for the replicate The flags field of CDR_repl_attrs The flags field of the CDR_repl_attrs structure can take the following values The setting of the flags field influences the values in the primary and secondary fields where applicable set the appropriate related field The arguments of the CDR_repl_attrs structure specify the attributes of the replicate as follows Flags Field Macros Description Conflict resolution option Conflict resolution option Conflict resolution scope Conflict resolution scope Diagnostic information Diagnostic information A_PRIMARY The structure member attrs primary specifies the primary resolution method for the replicate The member attrs primary method specifies the conflict resolution method A_SECONDARY The structure member attrs secondary specifies the secondary resolution method for the replicate The member attrs secondary method specifies the type The member attrs secondary is only valid if the primary m
106. _orders AA101 AA_g_usa_items AA102 AA_g_usa_stock AA103 AA_g_usa_state AA104 Enterprise Replication Manager Wizards 9 19 Describing the Replicates Describing the Replicates After you choose a naming scheme the wizard proceeds to ask for attributes of the replicates with pages similar to the wizard pages described in Defining a Replicate on page 9 4 Wizard pages ask you to m choose a conflict resolution rule m choose options for the replicates such as transaction scope and message format m choose a replication frequency m choose the database servers that will participate in the replicate 9 20 Guide to Informix Enterprise Replication Describing the Participants Describing the Participants The next wizard page asks you to choose the tables to replicate Figure 9 13 shows a list of participant descriptions ready for the generic wizard to create the replicates Figure 9 13 Tables to Replicate Update Anywhere Replication System Wizard informix orders w False informix items item num where m False informix stock w False informix state E False Enterprise Replication Manager Wizards 9 21 Describing the Participants To prepare the information in Figure 9 13 click Add for each table that you want to add Enter the participant attributes as in Figure 9 14 and click OK Fill in a set of attributes for each table that should be replicated Add Participant Definition Figure 9 14 Participa
107. _serv to remove bangor as a participant in any replication In both cases replication messages intended for bangor might be discarded The replication is still active on ames and milpitas Step 9 Stop Replication with cdr_stop_repl When the replication is no longer required the administrator can issue the cdr_stop_rep1 call This API stops data capture at bangor ames and milpitas After all table changes have propagated queues have emptied the tables will be consistent During the period that the queues are emptying the replication is quiescent no data is being captured but data is still being propagated for the replication When the queues have drained on all the sites the replication returns to the inactive state Fine Tuning Enterprise Replication D 9 WIN NT SQLHOSTS Registry Key When you install the database server the setup program creates the following key in the Windows NT registry HKEY_LOCAL_MACHINENSOFTWAREXINFORMIXASQLHOSTS This branch of the HKEY_LOCAL_MACHINE subtree stores the sqlhosts information Each key on the SOLHOSTS branch is the name of a database server When you click the database server name the registry displays the values of the HOST OPTIONS PROTOCOL and SERVICE fields for that particular database server Each computer that hosts a database server or a client must include the connectivity information either in the SOLHOSTS registry key or in a central registry When the client appli
108. a tions Data replication generates and manages multiple copies of data at one or more sites which allows an enterprise to share corporate data throughout its organization This chapter introduces the following information m Data replication types m Data replication capture mechanisms m Informix Enterprise Replication features Data Replication Types Data replication can be synchronous and asynchronous Each data repli cation type provides different capabilities and strengths Informix database servers allow you to use either type of replication Enterprise Replication provides asynchronous data replication Synchronous Data Replication In synchronous data replication the replicated data is updated immediately when the source data is updated Synchronous data replication uses the two phase commit technology to protect data integrity In a two phase commit a transaction is applied only if all interconnected distributed sites agree to accept the transaction Data Replication Overview 1 3 Asynchronous Data Replication Figure 1 1 illustrates the two phase commit The database server that initiates the transaction Server A asks each participating server whether it is ready to accept the transaction In this figure Server Z has not responded therefore the transaction does not commit on any database server Figure 1 1 Server A Two Phase Commit Technology Database server Are you ready d accept a transaction s
109. a repli cation server you must use the name of the database server group g_usa rather than the database server name Line 2 This line displays the replication server that you defined so that you can verify that the definition succeeded The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_usa 1 Active Local 3 6 Guide to Informix Enterprise Replication Preparing for a Primary Target Replication Line 3 Define the second database server italy as a replication server The connect option allows you to define italy on the s2 computer while working at the s1 usa computer The sync option instructs the command to use the already defined replication server g_usa as a pattern for the new definition The sync option also links the two replication servers into a replication environment Tip In all options except the connect option Enterprise Replication uses the name of the database server group to which a database server belongs instead of the name of the database server itself Line 4 Verify that the second definition succeeded The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_italy 8 Active Connected JUN 14 14 38 44 1999 g_usa 1 Active Local Lines 5 through 7 Lines 5 through 7 define a replicate These lines are all one command The backslashes at the end of lines 5 and 6 indicate that the command continues on the ne
110. a table that should be replicated use the name of the database server m nall other cases use the name of the database server group Replication Examples 3 5 Primary Target Example Using the CLU Primary Target Example Using the CLU This section contains a simple example of primary target replication In primary target replication only changes to the primary table are replicated to the other tables in the replicate Changes to the secondary table s are not replicated Preparing for a Primary Target Replication The following example defines the g_usa and g_italy database server groups as Enterprise Replication servers and creates a replicate repl1 1 cdr define server init g_usa 2 cdr list server 3 cdr define server connect italy init sync g_usa g_italy 4 cdr list server 5 cdr define replicate conflict ignore repll 6 P stores g_usa informix manufact select from manufact A 7 R stores g_italy informix manufact select from manufact 8 cdr list replicate 9 cdr start replicate repll 10 cdr list replicate Line 1 Before replicating data you must define the database servers as replication servers A replication server is a database server that has an extra database that holds replication information Line 1 creates and populates the database that defines the usa database server as a replication server The init option specifies that this server is a new replication server When you define
111. about the SELECT statement refer to the Informix Guide to SQL Syntax Database Server Groups Except in the Connect option the CLU uses the name of the database server group instead of the more familiar database server name that is the name specified in the INFORMIXSERVER environment variable for all references to database servers This manual also refers to a database server group as a server group Typically a server group includes only one database server However if the computer has multiple network protocols and or network interface cards the server group includes all aliases for the database server Enterprise Repli cation treats the server group as one object whether it includes one or several database server names If you use both DBSERVERNAME and DBSERVERALIASES DBSERVERNAME should refer to the network connection and not to a shared memory connection For information about database server aliases refer to the Admin istrator s Guide for Informix Dynamic Server 2000 Server Groups on UNIX On UNIX a server group is defined in the sqlhosts file In the following example line 2 describes the database server aserver Lines 3 and 4 define two more database servers that are aliases for aserver Line 1 defines a server group g_aserver that includes aserver bserver and aserver_shm 1 g_aserver group z i 27 2 aserver ontlitcp myhost svcname2 g g_aserver 3 bserver ontlitcp myhost svcname9 g g_aserver 4 aserver_shm on
112. about the WITH CRCOLS clause refer to the Informix Guide to SQL Syntax If a table that you plan to replicate includes cdrserver and cdrtime the state ments that you use for unloading the data must explicitly name the shadow columns If you use FROM tablename to the data to unload the data from the shadow columns will not be unloaded To include the shadow columns in the unloaded data use a statement like the following statement SELECT cdrserver cdrtime FROM tablename Using the High Performance Loader The HPL provides a high speed tool for moving data between databases For information about HPL refer to the Guide to the High Performance Loader How you use the HPL depends on how you defined the tables to replicate If the table definition included the WITH CRCOLS clause then you must take special steps when you unload the data When you use the WITH CRCOLS clause with the CREATE TABLE statement the database server creates two shadow columns cdrserver and cdrtime that contain replication information 6 4 Guide to Informix Enterprise Replication Using the onunload and onload Utilities If the table contains shadow columns you must perform the following additional steps 1 Include the cdrserver and cdrtime columns explicitly in the query statement when you unload the data 2 Include the cdrserver and cdrtime columns in your map when you load the data 3 Use Express mode to load data that contains the cdrse
113. aluator statistics Grouper general statistics Grouper global list Grouper global list expand open transactions Grouper compression statistics Clear grouper compression statistics Grouper table partition statistics Grouper replicate statistics Grouper serial list head Sl Grouper serial list Sx Grouper serial list expand open transactions onstat onstat Grouper transaction statistics The onstat g nif Command The g nif option of the onstat command prints statistics about the network interface The network interface information includes a summary of the number of buffers sent and received for each site The g nif option is used primarily as a debugging tool and by Informix Technical Support It can be helpful when data is not replicating The onstat g nif command has the following formats g nif g nif modifier F 4 Guide to Informix Enterprise Replication The onstat g que Command The modifier can have the values that the following table shows Modifier What the Command Prints all The sum and the sites sites The NIF site context blocks serverid Information about the replication server whose groupID is serverid sum The sum of the number of buffers sent and received for each site The onstat g que Command The g que option of the onstat command prints statistics for the high level queue interface The g que option is used primarily as a debugging t
114. ame Expanded Replication Manager g usa ro Here_Is_an_Extraordinaril mg This_ls_A_Very_Long_Name_ Enterprise Replication Menus 8 9 The Replication Manager Main Window The Replication Manager Main Window The main window provides a central point of control for the Replication Manager You can define modify delete and view database servers repli cates and groups and access hierarchical views scripting views and the event monitor Figure 8 3 shows the header and toolbar of the main window To access menu items click a menu from the title bar and then choose the menu item You can also select a replicate group or database server and press the right key of your mouse to access the menu items y Figure 8 3 ot Replication Manager g_italy ie Manager Main ej Jaw Window Click the server icon to display all servers defined for Enterprise Replication Click the global catalog icon to reload the catalog for the selected server Click the replicate icon to View a specific server by AN display all replicates defined selecting the server from the Click the What s This icon to for Enterprise Replication server list box invoke context sensitive help Using the Global Catalog Icon When you click the global catalog icon ERM reloads the global catalog of the server appearing in the server list box the currently selected server If you have been using the CLU as well as ERM the current
115. an 6 Active Connected Augl9 14 20 03 1999 g_usa 1 Active Local Line 6 Line 6 lists the replication servers as seen by the denver replication server The nonroot server denver has a complete global catalog of replication infor mation so it knows all the other servers in its replication system However denver knows the connection status only of itself and its parent usa The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_boston 3 Active g_denver 27 Active Local g_italy 8 Active g_japan 6 Active g_usa 1 Active Connected Aug 19 14 28 22 1999 Line 7 Line 7 defines miami as a leaf server whose parent is boston Replication Examples 3 15 Primary Target Example Using ERM WIN NT Line 8 Line 8 lists the replication servers as seen by miami a leaf server As a leaf replication server miami has a limited catalog of replication information It knows only about itself and its parent The command returns the following information SERVER ID STATE STATUS CONNECTION CHANGED g_boston 3 Active Connected Augl9 14 35 17 1999 g_miami 4 Active Local Lines 9 Line 9 lists details about the usa replication server The server is a hub that is it forwards replication information to and from other servers It uses the default values for time out sendq recvq and atsdir The command returns the following information NAME ID ATTRIBUTES g_usa 1 timeout 15 hub sendq rootdbs recvq rootdbs ats
116. and Sample Code Conventions Examples of SOL code occur throughout this manual Except where noted the code is not specific to any single Informix application development tool If only SQL statements are listed in the example they are not delimited by semicolons For instance you might see the code in the following example CONNECT TO stores_demo DELETE FROM customer WHERE customer_num 121 COMMIT WORK DISCONNECT CURRENT 12 Guide to Informix Enterprise Replication Additional Documentation To use this SQL code for a specific product you must apply the syntax rules for that product For example if you are using DB Access you must delimit multiple statements with semicolons If you are using an SQL application programming interface API you must use EXEC SQL at the start of each statement and a semicolon or other appropriate delimiter at the end of the statement Tip Ellipsis points in a code example indicate that more code would be added in a full application but it is not necessary to show it to describe the concept being discussed For detailed directions on using SOL statements for a particular application development tool or SQL API see the manual for your product Additional Documentation For additional information you might want to refer to the following types of documentation On line manuals Printed manuals On line help Error message documentation Documentation notes release notes and ma
117. and ID Columns The SERVER and ID columns display the name of an Enterprise Replication server and its replication ID 11 50 Guide to Informix Enterprise Replication Usage The STATE Column The STATE column can have the following values m Active m Quiescent m Suspended The STATUS Column The STATUS column can have the following values Connected Disconnect Dropped Error Detected Local Timeout The CONNECTION Column The CONNECTION column displays the most recent time that the status of the server connection was changed Showing Details about a Single Replication Server When the cdr list server command includes the name of a database server group the command displays the attributes of that database server For example cdr list server g_usa might give the following output NAME ID ATTRIBUTES g_usa 3 timeout 15 sendq rootdbs recvq rootdbs atsdir tmp risdir tmp Command Line Utility 11 51 Usage Examples In the following examples usa and italy are root servers denver and boston are nonroot servers and miami is a leaf server The usa server is the parent of denver and boston and boston is the parent of miami NAME ID ATTRIBUTES cdr list server g_usa g_usa 1 timeout 15 hub sendq rootdbs recvq rootdbs atsdir tmp risdir tmp cdr list server c denver g_denver g_denver 27 root g_usa sendq recvq atsdir ix myats risdir cdr list server c italy g_denver g_denver 27 root g_usa forward g_usa
118. ansaction fails for any reason constraint violation duplicate and so on all the buffers in the replication message that compose the transaction are written to a local operating system file You can use the ATS files to identify problems or as input to custom written utilities that extract or reapply the aborted rows In some cases such as with long transactions the database server can abort transactions In these cases Enterprise Replication does not generate an ATS file Diagnosing Enterprise Replication 10 3 Preparing to Use ATS UNIX WIN NT Preparing to Use ATS Failed transactions are not automatically recorded in ATS files To collect ATS information perform the following steps 1 Specify a directory where ATS files will be stored when you define a server for Enterprise Replication The pathname that specifies the ATS directory can be no longer than 256 bytes a With ERM set the spooling directories on the Declare Server display that Figure 3 6 on page 3 22 shows a With the CLU include the ats option with cdr define server If you do not specify an ATS directory Enterprise Replication stores the ATS files in the tmp directory If you do not specify an ATS directory Enterprise Replication stores the ATS files in the tmp directory of the drive that contains INFORMIXDIR Specify that ATS should be active when you define a replicate In expert mode you can use ATS for some replicates and no
119. arts a prefix and a postfix The prefix is an arbitrary string that identifies this group of replicates It must start with an alphanumeric character The postfix can be a number or an attribute of the participant 9 18 Guide to Informix Enterprise Replication Choosing a Naming Scheme When you select an attribute for the postfix the wizard separates the prefix from the postfix with an underscore When you choose a number for the attribute the wizard does not put an underscore between the prefix and postfix If you choose ZZ for the prefix table for the attribute or 11 for the starting number the following table shows the generated names for repli cates on the orders items stock and state tables Using an Attribute Using a Numeric Postfix ZZ_orders ZZ11 ZZ_items ZZ12 ZZ_stock ZZ13 ZZ_state ZZ14 Naming Primary Target Replicates For generic primary target replicates the generated names can have two or three parts a prefix and two attributes or a prefix and a number In the following example AA is the prefix and g_usa is the primary server The left hand column shows the generated names for replicates on the orders items stock and state tables if you choose primary participant for the first attribute and table for the second attribute If instead you choose to number the repli cates starting with 101 the right hand column of the table shows the generated names Using an Attribute Using a Numeric Postfix AA_g_usa
120. as Figure 3 30 shows or the server display as Figure 3 31 shows q Figure 3 30 ot Replication Manager g japan Edo from Replicate Display Inactive Ba gusa Inactive E Figure 3 31 oi Replication Manager g japan Select from Server Display ojm A EMM g_italy Active 6 repl3 Am 9japan NOS g_usa Active 3 46 Guide to Informix Enterprise Replication Adding a Participant to reol4 Selecting a New Participant The Add Participant wizard displays an introductory page Click Next The next wizard page Figure 3 32 asks which servers you want to add to the replicate Select g japan click Add and then click Next Figure 3 32 Select New Participant g_japan Replication Examples 3 47 Activating the Replicate Specifying a Table and Columns The next two wizard pages ask you to specify the participant attributes and the columns to replicate Use the discussions in Selecting a Table on page 3 30 and Selecting the Columns on page 3 31 as guides for completing the pages When you click Finish ERM adds the new participant g japan to repl4 ERM does not show a summary page before it creates the new participant Activating the Replicate On the main ERM display click the replicate icon and then click the plus beside repl4 to display the database servers that are participants in the replicate The display as Figure 3 33 indicates shows that all participants in the repl
121. at it does not let you toggle between expert and nonexpert modes Help Offers the same options as the Help menu of the ERM main window When you open the Replication Scripting View ERM displays a window with two panes The left hand pane shows the replication environment that you are scripting That environment can be a copy of your current replication environment an environment that you previously saved or a new environment Enterprise Replication Menus 8 39 Replication Scripting View Menus When you select an object the right hand pane displays the characteristics of the objects The little pencil icon shows which items you can change To change an item right click on the item and choose the action to take Figure 8 13 shows a sample scripting view Figure 8 13 Replication Scripting View Replication Scripting View Replication System 4 repl2 Name A Transaction Conflict Resolutio Ignore Conflict Resolutio y MA Stored Procedure NA Optimized Stored i HA repl4 SES Replication Servers AB g_boston AB g_denver AB g_italy gos g_japan AB g_miami AB g_milan AB g_tokyo a False Triggers 8 40 Guide to Informix Enterprise Replication Enterprise Replication Manager Wizards In ThisChapter o m sor mba ea A a Bes 9 3 Defining a Replicate Ea aa e as td 4 9 4 Defining a Replicate Name ue OSE Rie a She ene OL Choosing a Conflict Resolution Proced
122. ate Conflict Resolution Rules Replicate Example Participant Replicate Group Ease of Use Increased Performance Catalog Replication Types ae Primary Target Replication One to Many Replication Many to One Replication Update Anywhere Replication Conflict Resolution 4 Conflict Resolution Rules Resolution Scope 23 2 3 2 4 2 5 2 7 2 12 2 12 2 13 2 13 2 14 2 14 2 15 2 15 2 15 2 15 2 15 2 16 2 16 Replication Data Evaluating Data for Replication Evaluating Time Evaluating Images of a Row Processing in Parallel Distributing Data Applying Replicated Data 2 2 Guide to Informix Enterprise Replication 2 17 2 17 2 17 2 17 2 18 2 19 2 19 In This Chapter This chapter introduces the following Enterprise Replication features Replication topologies Replication objects Replication types Conflict resolution Replication Data The next chapter Chapter 3 Replication Examples presents simple replication examples that use some of the objects defined in this chapter Enterprise Replication Topologies Enterprise Replication topology describes connections that replication servers make to interact with each other You must define the replication topology within the topology of the physical network but the replication topology is not synonymous with the physical network topology The order in which you define the database servers for replica
123. ation Servers A Optimized Stored i TOS g_boston AB g_denver AB g_italy a g_japan onical Messag B g_miami Triggers Enterprise Replication Manager Wizards 9 23 Diagnosing Enterprise Replication In This Chapter 2 be a vA Ga we cA a we AR a Be 10 3 Aborted Transaction Spooling 2 2 2 2 1 we ee ee 10 3 Preparing to Use ATS 2 2 2 we en 10 4 BYTE and TEXT Information in ATS Files 2 2 2 1 10 8 Row Information Spooling 2 2 1 ee ee ee 10 9 BYTE and TEXT Information in RIS Files 2 1 10 11 Replication Event Monitor Messages we 10 14 10 2 Guide to Informix Enterprise Replication In This Chapter Enterprise Replication provides tools to help you diagnose problems that arise during replications The aborted transaction spooling ATS and row information spooling RIS files contain information about failed transac tions The Replication Manager logs control events in the Replication Event Monitor This chapter describes the ATS and RIS files and provides a list of Replication Event Monitor log events The onstat command which Appendix F discusses displays statistics that you can use to diagnose problems Aborted Transaction Spooling When ATS is active all failed replication transactions are recorded in ATS spool files Each file that ATS produces contains all the information pertinent to a single failed transaction If a replicated tr
124. ation data for replicates defined in a replicate group This function is valid only on a group that has been suspended Syntax include cdrapi h int cdr_resume_group group time char group time_t time unused group is the replicate group name time is not used but cannot be omitted Use time_t 0 for that argument Usage The cdr_resume_group function causes the replicates contained in the replicate group group to enter the active state that is to capture and send replication data for all participants API Functions 12 35 cdr_resume_repl cdr_resume_repl The cdr_resume_repl function resumes delivery of replication data Syntax include cdrapi h int cdr_resume_repl repl time char repl time_t time unused repl is the replicate name time is not used but cannot be omitted Use t ime_t 0 for that argument Usage The replicate rep enters the active state that is to capture and send repli cation data for all participants If rep is contained in a replicate group the call fails To resume delivery of replication data to a replicate group see cdr_resume_group on page 12 35 12 36 Guide to Informix Enterprise Replication cdr_resume_serv cdr_resume_serv The cdr_resume_serv function resumes delivery of replication data to a database server Syntax include cdrapi h int cdr_resume_serv db_server servers time which char db_
125. ation imposes the following operational limits m Enterprise Replication supports replication only on Dynamic Server m High availability data replication HDR cannot run concurrently with Enterprise Replication m Replication is restricted to base views That is you cannot define a replicate on a table that is a view m A database server can participate only once in a replicate SQL Statement Use After you define Enterprise Replication on a table by including that table as a participant in a replicate you cannot execute any operation that changes the structure of the table Setting Up Your Replication Environment 5 3 Forbidden SQL Statements Forbidden SOL Statements You cannot use the following SOL statements against a table that is included in a replicate m DROP TABLE m RENAME TABLE m ALTER FRAGMENT Limited SQL Statements The following additional limitations also apply to tables defined for replication Do not remove the primary key constraint Do not rename add or drop columns Do not modify a column type Do not add or drop rowids Do not add or drop CRCOLS Do not modify the primary key column s For example do not alter the column to add default values or other constraints Do not create clustered indexes Permitted SQL Statements Enterprise Replication permits the following SQL statements with no limitations SET object mode START VIOLATIONS TABLE STOP VIOLATIONS TABLE CREAT
126. base server that is in the group This use of g_ is only a convention g_ is not required syntax If you prefer you can give your database server group the same name as the first database server in the group In that case the term server can refer to either the database server group or the database server In the following example the first line defines a database server group and the second line defines a database server that is a member of the srvB server group srvB group 1 83 svrB ontlitcp smoke svcname g srvB For more information about database server groups refer to your Administrator s Guide 12 4 Guide to Informix Enterprise Replication Time Specifications Time Specifications When you set a frequency for replication in cdr_define_rep1 or cdr_modify_repl state the time in the local time unless the TZ environment variable is set In the global catalog all times are stored in Greenwich mean time GMT Several API functions specify a time variable that has no function You must nevertheless fill in a dummy value for the variable Identifiers Identifiers are the names of objects such as database names table names and replicate names For more information refer to Viewing Long Identifiers on page 8 8 API Structures The API functions documented in this chapter use the following structures which are also documented in the following directories m INFORMIXDIR incl esql cdrapi h UNIX m IN
127. be replicated The participant modifier must be enclosed in quote marks SELECT Element Purpose 3 um J FROM table WHERE Clause Restrictions Name of a column in the table The column must exist Identifiers p 8 8 specified by the participant The table specified by the Must be the table name only You Identifiers p 8 8 participant cannot specify an owner or a database server You cannot specify a synonym or a view WHERE Clause Clause that specifies a subset of WHERE clause table rows to be replicated syntax refer to Informix Guide to SQL Syntax Restrictions on the SELECT Statement The following restrictions apply to a SELECT statement that is used as a participant modifier The FROM clause of the SELECT statement can reference only a single table The statement cannot include a join or a subquery The table in the FROM clause must be the table specified by the participant The columns selected must include the primary key The columns selected cannot include smart large objects The columns selected can include TEXT and BYTE data Command Line Utility 11 11 Database Server Groups UNIX m The columns selected can include only limited user defined types For information about using user defined data types refer to Repli cating User Defined Data Types on page 5 15 m The statement cannot contain user defined routines For detailed information
128. ber of a specific Mustbethe number of an errorin Integer error the error table 11 44 Guide to Informix Enterprise Replication cdr error The options for cdr error have the meanings shown in the following table Options Long Form Short Form Meaning no options Print the current list of errors After the errors have specified been printed mark them as reviewed all a When used with the move option move the error table to dbspace on all defined servers Otherwise print all errors including those already reviewed follow f Continuously monitor the error table move m Move the error table to the dbspace dbspace_name nomark n Do not mark errors as reviewed prune p Prune the error table to those times in the range from first to last If first is omitted then all errors earlier than last are removed seq S Remove the single error specified by server seqno from the error table zap Z Remove all errors from the error table Usage The cdr error command allows you to examine replication errors on any replication server Sometimes a CLU command can succeed on the server on which it is executed but fail on one of the remote servers For example if you execute cdr define replicate on server1 but the table name is misspelled on server2 the command succeeds on server1 and appears to have completed successfully You can use cdr error c server2 to see why replication is not occurring The cdr error
129. beta and g_gamma respectively Assume that alpha is the database server from which you want to get the initial copy of the data 1 Declare server delta to Enterprise Replication For example cdr def ser c delta I S g_alpha g_delta At the end of this step all servers in the replication environment include information about delta and delta has information about all other servers 2 Add delta as a participant to replicate zebra For example cdr cha rep a zebra dbspace g_delta owner tablel This step updates the replication catalog The servers alpha beta and gamma do not queue any qualifying replication data for delta because the replicate on delta although defined has not been started 3 Suspend server to delta on alpha beta and gamma cdr sus ser g_alpha g_beta g_gamma As a result of this step replication data is queued for delta but no data is delivered 6 8 Guide to Informix Enterprise Replication Beginning Work Without Replication Start replication for replicate zebra on delta cdr sta rep zebra g_delta This step causes servers alpha beta and gamma to start queueing data for delta No data is delivered to delta because delta is suspended delta queues and delivers qualifying data if any to the other servers Informix recommends that you do no transactions on delta that affect table table1 until you finish the synchronization process Unload data from table table1 using the UNLOAD statement or the un
130. can perform the same actions The second command cdr delete server c italy g_ italy connects to server italy and removes Enterprise Replication from italy That is it removes the syscdr database and removes or stops other components of Enterprise Replication Figure 11 1 shows a replication environment with three replication servers g_usa g italy and g japan Figure 11 1 Three Replication Servers Command Line Utility 11 41 cdr delete server cdr delete cdr delete cdr delete cdr delete cdr delete a Fon 11 42 Guide to Informix Enterprise Replication server server server server server To remove Enterprise Replication from this environment issue the following commands from the computer where the usa replication server resides g_italy c italy g_italy g_japan c g_japan g_usa Line 1 removes connections between the italy replication server and all other servers in the replication system usa and japan and removes any queued data Line 2 removes all replication information including the syscdr database from the italy database server Similarly lines 3 and 4 remove the japan replication server Finally line 5 removes the replication information from the usa replication server itself cdr disconnect server cdr disconnect server The cdr disconnect server command stops a server connection Syntax server_group cdr disconnect server
131. cation runs on the same computer as the database server they share a single SOLHOSTS registry key The Location of the SQLHOSTS Registry Key The Location of the SQLHOSTS Registry Key When you install the database server on Windows NT the installation program asks where you want to store the SQLHOSTS registry key You can specify one of the following two options The local computer where you are installing the database server Another computer in the network that serves as a central shared repository of sqlhosts information for multiple database servers in the network Using a shared SOLHOSTS registry key relieves you of the necessity to maintain the same sqlhosts information on multiple computers However the hosts and services files on each computer must contain information about all computers that have database servers If you specify a shared SQLHOSTS registry key you must set the INFORMIX SOLHOSTS environment variable on your local computer to the name of the Windows NT computer that stores the registry The database server first looks for the SOLHOSTS registry key on the INFORMIXSQLHOSTS computer If the database server does not find an SQLHOSTS registry key on the INFORMIX SOLHOSTS computer or if INFORMIXSQLHOSTS is not set the database server looks for an SQLHOSTS registry key on the local computer You must comply with Windows NT network access conventions and file permissions to ensure that the local computer has acce
132. chine notes Related reading On Line Manuals An Answers OnLine CD that contains Informix manuals in electronic format is provided with your Informix products You can install the documentation or access it directly from the CD For information about how to install read and print on line manuals see the installation insert that accompanies Answers OnLine Informix on line manuals are also available on the following Web site www informix com answers Introduction 13 Printed Manuals WIN NT UNIX WIN NT Printed Manuals To order printed manuals call 1 800 331 1763 or send email to moreinfo informix com Please provide the following information when you place your order m The documentation that you need m The quantity that you need m Your name address and telephone number On Line Help Informix provides on line help with each GUI that displays information about those interfaces and the functions that they perform Use the help facil ities that each GUI provides to display the on line help Error Message Documentation Informix software products provide ASCII files that contain all of the Informix error messages and their corrective actions To read error messages and corrective actions on UNIX use one of the following utilities Utility Description finderr Displays error messages on line rofferr Formats error messages for printing 4 To read error messages and corrective actions in Windows envi
133. ciled and the order is finally shipped In a workflow replication system application modules can be distributed across multiple sites and databases Data can also be replicated to sites that need read only access to the data for example if order entry sites want to monitor the progress of an order A workflow replication system like the primary target replication system only allows unidirectional updates Many facts that you need to consider for a primary target replication system should also be considered for the workflow replication system However unlike the primary target replication system availability can become an issue if a database server goes down The database servers in the workflow replication system rely on the data updated at a previous site Consider this fact when you select a workflow replication system Factors in Primary Target Systems The following sections describe some of the factors to consider when you select a primary target replication system Selecting Enterprise Replication Systems 4 7 Selecting Data for Primary Target Replication Selecting Data for Primary Target Replication The requirements for unique primary keys limit the use of the SERIAL and SERIALS data types in schema that participate in a replication system You can replicate from a serial data type column but the destination column must be an integer When Enterprise Replication applies rows in this situation it sets the destination in
134. cipant with the CLU refer to cdr change replicate on page 11 22 Changing Replicate States The second group of choices on the Replicate menu allows you to change the state of a replicate or participant A replicate can be in one of the following states m Active m Inactive m Quiescent m Suspended A participant can be either active or inactive You cannot suspend an individual participant only a replicate If any participant of the replicate is active the replicate itself is active If all participants are inactive the replicate is inactive 8 14 Guide to Informix Enterprise Replication Start Replicate g_italy g_japan Changing Replicate States Active When a replicate is in active state Enterprise Replication captures data from the logical log and transmits the captured data to participants To change the state of a replicate to active select the replicate and then choose Replicate gt Start Replicate The Start Replicate dialog box lets you select the participants to start in the replicate as shown in the left hand display in Figure 8 5 Figure 8 5 Start Replicate and Stop Replicate Dialog Boxes g_italy g_japan If you select a participant the Replicate menu changes to include Start Participant instead of Start Replicate When you choose Start Participant only the single participant that you selected becomes active To start a replicate or participant with the CLU refer to cdr
135. columns of the syscdrsync_txn table refer to Columns of the Transaction Tables on page B 3 syscdrserver The syscdrserver table contains information about database servers that have been declared to Enterprise Replication Column Type servid integer servername char 128 connstate char 1 connstate integer change servstate char 1 ishub char 1 isleaf char 1 Description Replication server ID Database server group name Status of connection to this database server C Connected D Connection disconnected will be retried T Idle time out caused connection to terminate X Connection closed by user command Connection unavailable until reset by user Time that connection state was last changed Status of this database server A Active S Suspended H Holding Q Quiescent initial sync state only Y server is a hub N server is not a hub Y the server is a leaf server N the server connection is not a leaf server 1 of 2 SMI Tables for Enterprise Replication B 15 syscdrsync_buf Column Type Description rootserverid integer The identifier of the root server forwardnodeid integer The identifier of the parent server idletimeout integer Idle time out sendqueueloc char 128 Dbspace name that indicates where the send queue is located rcvqueueloc char 128 Dbspace name that indicates where the receive queue is located atsdir char 256 ATS directory spooling name risdir char 25
136. connect server server_ group p 11 8 Element Purpose Restrictions Syntax server_group Name of server group to resume The server group must be Server Group defined for replication and have p 11 12 been disconnected Usage The cdr connect server command re establishes a connection to the server server_group 11 24 Guide to Informix Enterprise Replication car define group cdr define group The cdr define group command defines a replicate group Syntax cdr define group a D repl_group eo N A Connect Option A p 11 8 Banm NE ae parallel A Frequency Options p 11 14 Element Purpose Restrictions repl_group Name of replicate group to create The name must be unique and Identifiers p 8 8 cannot be the same as a replicate name replicate Name of a replicate to be The replicate must exist Identifiers p 8 8 included in the group The options in cdr define group have the meanings that the following table shows Options Long Form Short Form Meaning parallel p Process all groups in parallel sequential S Process all groups sequentially Command Line Utility 11 25 car define group You can specify parallel options only when replicates in the group have disjoint data domains If neither the parallel nor sequential option is set the default is sequential processing Usage The cdr define group command defines a replicate group Any
137. copy of the global catalog might be out of date 8 10 Guide to Informix Enterprise Replication Using the Whats This Icon Using the What s This Icon When you click the What s This icon the cursor changes to an arrow with a question mark Drag this icon to the object for which you want help and click the left mouse button The File Menu The File menu includes the following options New Script expert mode only Open Script expert mode only Event Monitor Exit Creating Scripts The New Script and Open Script menu options open the Replication Scripting View This view lets you create modify and save different repli cation environments For more information refer to Replication Scripting View Menus on page 8 39 Monitoring Replication Events The Event Monitor option lets you view a summary of replication errors and warnings Enterprise Replication records warnings or severe errors that occur on a remote replication server it does not record error messages from the local replication server to the Replication Event Monitor From the Event Monitor display you can select a single error and ask the event monitor to show more detail about that error You can also mark individual events as reviewed delete selected events or export the infor mation to a text file for printing Enterprise Replication Menus 8 11 The Replicate Menu The Replicate Menu The Replicate menu lets you define and control rep
138. core The remaining characters can be letters numbers or underscores Most identifiers can be 18 bytes long However replicates and replicate groups can be 128 bytes long For more information about identifiers see the Informix Guide to SQL Syntax In Informix Dynamic Server 2000 all identifiers can be 128 bytes long However if you have any database servers in your replication environment that are from an earlier version you must follow the length restrictions for that version The location of files such as the location of the ATS files can be 256 bytes User login IDs can be a maximum of 32 bytes The owner of a table is derived from a user ID and is thus limited to 32 bytes Although long identifiers for objects are permitted most objects have reasonably short names Therefore the displays in the Replication Manager are designed to accommodate identifiers that are not very long When you encounter a long name in the Replication Manager you can click on the name to see the full name expanded or use the scroll bar to view the entire name 8 8 Guide to Informix Enterprise Replication Viewing Long Identifiers For example in Figure 8 1 the long replicate names are truncated In Figure 8 2 the cursor is pointing to the first replicate causing the replicate name to expand to its full length Figure 8 1 Replication Manager g Long P Name Truncated HA This_Is_A_Very_Long_Name_ Figure 8 2 Long Replicate N
139. ct Resolution Rule Using Cascading Deletes Using Cascading Deletes If the source table and the target table define cascading deletes the children rows that delete as a result of the cascading delete on a parent row on the source database server are also sent to the target database server When this transaction is applied on the target database server the cascading delete is invoked when the parent row is processed and the children rows are deleted Subsequently when deletes are processed on the children an error might result because the rows were already deleted The table in Figure 7 13 indicates how Enterprise Replication resolves cascading deletes with conflict resolution scopes and rules Figure 7 13 Resolving Cascade Deletes Conflict Resolution Scope Actions on Delete Errors Result Time stamp Ignore Ignore Row by row or Note as replication Process children rows transaction exceptions Transaction Report as errors Abort entire transaction Row by row Report as errors Reject row Using Triggers If the trigger option is enabled triggers that are defined on a table that is defined for replication are invoked when transactions are processed on the target database server Similar to the cascading deletes if the same triggers are defined on both the source and target tables any insert update or delete operation that the triggers generate are also sent to the target database server These operations can result in e
140. ctions are eligible for replication Evaluating Images of a Row After Enterprise Replication evaluates the recorded time to determine whether a transaction should be replicated Enterprise Replication evaluates the initial and final images of a row and any changes that occur between the two row images to determine which rows to replicate Enterprise Replication Features 2 17 Evaluating Data for Replication Logical log Processing in Parallel Enterprise Replication evaluates the images of rows in parallel to assure high performance The records that qualify are collected into a transaction list and then passed to the Enterprise Replication reliable message queue for distri bution Figure 2 6 illustrates how Enterprise Replication uses parallel processing to evaluate transactions for replication Figure 2 6 Evaluating transactions for replication Processing in Transaction list Parallel for High Performance AVE ran Enterprise 1234 1235 candlestie Replication message queue HH After Enterprise Replication identifies transactions that qualify for repli cation Enterprise Replication transfers the transaction data to a message queue 2 18 Guide to Informix Enterprise Replication Distributing Data Distributing Data Enterprise Replication uses the message queue to ensure that all data reaches the a
141. cy types can be specified by setting the type member of the Description Replicate all data immediately Replicate data at the hour and minute interval specified by the hour and minute members of the structure Replicate data every day at the time specified by the hour and minute members of the structure Replicate data once a week at the time and day specified by the hour minute and day members of a structure where the day member contains a value between 1 and 7 where 1 Monday 2 Tuesday 3 Wednesday and so on Replicate data once a month at the time of day of the month specified by the hour minute and day members of the structure where the day member contains a value between 1 and 31 or L designating the last day of the month If a replicate group is defined over a set of existing replicates whose frequency type is not immediate data is replicated for the replicate group with respect to the earliest time that data was replicated for all replicates cdr_define_group If you add a replicate that uses time based frequency to an already existing group that uses the frequency type immediate then all the data from the newly added replicate is immediately sent to its targets even though the specified time has not arrived This allows the newly added replicate to assume the frequency attributes of the group with no pending data in its send queue It also prevents Enterprise Replication from replicating data out of order
142. d no data is sent for the suspended servers replicates or groups Enterprise Replication resumes evaluation of the logical log if required for the instance of Enterprise Replication at the replay position The replay position is the position where Enterprise Replication stops evaluating the logical log when cdr stop is executed If the evaluation process is running and the logical log ID for the replay position no longer exists when Enterprise Replication is started then the restart partially fails the database server log contains an error message stating that the replay position is invalid If the restart partially fails no database updates performed on the local database server are replicated Warning Informix recommends that you issue cdr start and cdr stop with extreme caution Use these commands during a period of little or no database activity and keep the downtime to a minimum Transactions that occur during this period are not replicated and hence tables will be unsynchronized 11 64 Guide to Informix Enterprise Replication cdr start Example The following example restarts Enterprise Replication processing on database server utah cdr start c utah Command Line Utility 11 65 car start group cdr start group cdr start group The cdr start group command starts the capture and transmittal of repli cation transactions for the replicates contained in a replicate group Syntax repl_ group Connec
143. d in a replicate group this command fails When repl_name is in a replicate group use the cdr stop group command on page 11 70 Command Line Utility 11 71 cdr stop replicate Example The following command connects to the database server lake and stops the replicate aRepl on server groups g_serverl and g_server2 cdr stop replicate c lake aRepl g_serverl g_server2 11 72 Guide to Informix Enterprise Replication cdr suspend group cdr suspend group The cdr suspend group command suspends delivery of replication data for replicates contained in a replicate group Syntax cdr suspend group repl_ group p 11 8 Element Purpose Restrictions Syntax repl_group Name of replicate group to The group must be a currently Identifiers p 8 8 suspend active group Usage The cdr suspend group command causes the replicates in the replicate group repl_group to enter the suspend state Information is captured but no data is sent for any replicate in the group The data is queued to be sent when the group is resumed You cannot remove replicates from a replicate group when the group is suspended Warning When a replicate group is suspended Enterprise Replication holds the replication data in the send queue until the group is resumed If lots of data is generated for the group while it is suspended the send queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize
144. d time and day of the month To ensure that replication occurs on the last day of every month select the word Last in the Day of month text box If you select 31 replication takes place only in months that have 31 days Important Time based replication is based on the local time not Greenwich mean gt time GMT If database servers participating in the replicate are in different time zones than the database server on which the time is set replication will occur at different times 9 8 Guide to Informix Enterprise Replication Selecting Servers to Participate in the Replicate Selecting Servers to Participate in the Replicate Figure 9 5 shows a select server wizard page This sample page is creating a primary target replicate in expert mode In nonexpert mode only one server could be chosen as the primary The select server page for update anywhere is similar to Figure 9 5 except that you do not need to specify which servers are primary or secondary because all servers in an update anywhere repli cation have equal status Figure 9 5 Select Servers Page Define Replicate Wizard g_miami g italy g_milan g_tokyo g_venice g_boston g_denver The Servers list box lists all replication servers in the replication environment To select the servers for your replicate click the server name or several server names and click Add All database servers in an update anywhere replicate must have
145. data item the trigger can activate the replication process The intent of this data capture mechanism is to protect the referential integrity of the data However when a trigger begins to transfer modified data items trigger based data capture does not keep track of transaction information Because trigger based capture does not keep track of transaction information customers and vendors must produce applications that ensure the referential integrity of the data Tip Triggers are used for many other purposes besides replication For a broader discussion of triggers refer to the Informix Guide to Database Design and Implementation Trigger Based Transaction Capture Trigger based transaction capture does not perform replication based on triggered data Instead data changes are grouped into transactions This data capture mechanism assures the referential integrity of the data but adds additional work that can affect system performance In trigger based transaction capture a single transaction might trigger several replications if it modifies several tables because the triggers are associated with the table In this case the trigger receives the whole trans action but the procedure that captures the data runs as a part of the original transaction thus slowing down the original transaction Figure 1 2 illustrates this type of replication 1 6 Guide to Informix Enterprise Replication Trigger Based Transaction Capture
146. defined using the API call cdr_define_repl The replication system will be defined with the name employeeinfo with participant database servers bangor ames and milpitas as follows general bangor employees SELECT FROM employees general milpitas employees SELECT FROM employees general ames employees SELECT FROM employees with resolution rules set to timestamp primary The replication system is defined in the global catalog with an initial state of inactive This state means that no replication data is captured or transmitted Fine Tuning Enterprise Replication D 7 Step 6 Prepare the Tables for Replication Step 6 Prepare the Tables for Replication The database administrator must ensure that the data in the tables is consistent across all sites before starting replication This example assumes that bangor contains the complete correct version of the table The following list shows actions necessary to prepare for replication m Lock the tables on bangor ames milpitas with a shared lock m Unload the authoritative copy of the table from bangor m Load new copies into ames and milpitas Step 7 Start Replication The API call cdr_start_repl is invoked with the name of the replicate This command starts data capture and queueing at all participating database servers Unlock the tables on bangor ames and milpitas After the completion of the start the replication system is active Data is being ca
147. depending on the conflict resolution scope you chose The following list describes each conflict resolution scope Row by row scope When you choose a row by row conflict resolution scope Enterprise Replication evaluates one row at a time It only applies replicated rows that win the conflict resolution with the target row If an entire replicated transaction receives row by row evaluation some repli cated rows are applied and other replicated rows might not be applied Transaction scope When you choose a transaction conflict resolution scope Enterprise Replication applies the entire transaction if the replicated transaction wins the conflict resolution If the target wins the conflict or other database errors are present the entire replicated transaction is not applied and rollback occurs A transaction scope for conflict resolution guarantees transactional integrity Important Enterprise Replication defers some constraint checking on the target gt tables until the transaction commits Ifa unique constraint or foreign key constraint violation is found on any row of the transaction at commit time the entire trans action is rejected regardless of the conflict resolution scope 7 14 Guide to Informix Enterprise Replication Time Stamp Conflict Resolution Rule Time Stamp Conflict Resolution Rule The time stamp rule evaluates the latest time stamp of the replication against the target and determines a winner The ti
148. dir tmp Primary Target Example Using ERM This example uses the Enterprise Replication Manager ERM to perform the same simple primary target replication that the Primary Target Example Using the CLU on page 3 6 shows To use ERM with Dynamic Server Version 7 31 install Informix Enterprise Command Center IECC From IECC choose Tools gt Enterprise Replication Manager To add or modify the SQLHOSTS connectivity information use the IECC Add Database Server wizard To use ERM with Dynamic Server Version 9 2 install ERM and the proper connectivity tools For information about preparing ERM for Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of this chapter 3 16 Guide to Informix Enterprise Replication Removing Previously Defined Replication Servers Removing Previously Defined Replication Servers After you define a database server as a replication server it remains a repli cation server Therefore if you have already done the examples in the first part of this chapter and want to start this example from the beginning you must remove the replication servers that you defined in the previous examples If you do not want to start from the beginning skip the next topic and go to Using Previously Defined Replication Servers on page 3 18 and continue with the rest of the example Deleting Previously Defined Replication Servers You can
149. does not exist Enterprise Replication returns an error Diagnosing Enterprise Replication 10 9 Row Information Spooling The RIS row information is written at the time that the data synchronization component finishes processing the replicated row and can therefore also provide the local row information The ATS file is written after the trans action is rolled back the locks for all the local rows are released and therefore do not include accurate local row data The RIS filename algorithm is analogous to the one that ATS uses with the ats prefix replaced by ris The RIS file that corresponds to the ATS file described in the previous section is for example ris purl sls4 D_2 960529_23 27 16 5 In addition to the four types of records printed in ATS the RIS file also includes the following information Label Name Description LRH Local row header Indicates if the local row is found in the delete table and not in the target table LRS Local row shadow Contains the server id and the time when the row is columns updated on the target server This line is printed only if the replicate is defined with a conflict resolution rule LRD Local row data Contains the list of replicated columns extracted from the local row and displayed in the same order as the replicated row data Similar to the replicated row data each column is separated by a and written in ASCII format When the spooling program encounters severe errors for
150. e If the time stamps are identical Enterprise Replication uses an SPL procedure to resolve the conflict Resolution Scope Each conflict resolution rule behaves differently depending on the conflict resolution scope you chose The following list describes each conflict resolution scope m Row by row scope Enterprise Replication resolves conflicts one row ata time m Transaction scope Enterprise Replication applies conflict rules to the entire transaction Transaction scope for conflict resolution guarantees transactional integrity 2 16 Guide to Informix Enterprise Replication Replication Data Replication Data Enterprise Replication uses a log based transaction capture mechanism to gather data for replication A log based transaction capture minimizes the effect on transaction performance it captures changes from the logical log instead of competing with transactions that access production tables Enterprise Replication reads the logical log to obtain the row images for tables that participate in a replicate These rows are passed to Enterprise Replication for further evaluation Evaluating Data for Replication Enterprise Replication evaluates transactions based on a distinct time and a change to a final image of a row Evaluating Time All Enterprise Replication commands are issued at distinct times Enterprise Replication records the time the command is issued and uses that time when it determines which transa
151. e a time option lets you specify the day on which an action should occur The string time can have the following formats Day of week To specify a specific day of the week give either the long or short form of the day followed by a period and then the time For example atime Sunday 18 40 or a Sun 18 40 specifies that the action should occur every Sunday at 6 40 P M The day of the week is given in the locale of the client For example with a French locale you might have atime Lunedi 3 30 or a Lun 3 30 The time and day are in the time zone of the server Day of month To specify a specific date in the month give the date followed by a period and then the time For example 1 3 00 specifies that the action should occur at 3 A M on the first day of every month The special character L represents the last day of the month For example L 17 00 is 5 P M on the last day of the month Daily To specify that replication should occur each day give only the time For example 4 40 specifies that the action should occur every day at 4 40 A M Command Line Utility 11 15 Example Using the Command Line Utility Intervals The e 7ength option lets you specify the interval between actions The length of time between replications can be either of the following formats m The number of minutes To specify the number of minutes specify an integer value For example e 60 indicates 60 minutes between replications m The number
152. e of the structure te data every day at the specified time te data once a week at the time and day specified by the hour minute and day members tructure where 1 Monday 2 Tuesday 3 Wednesday and so forth e data once a month at the time and he month specified by the hour and day members of the structure where the day member contains a value between l and 3 month or L designating the last day of the conflict method stored procedure wes dd XI a EJ XI Kj x EI E a EJ y stored procedure optomization option id CDR_GL_NAMESIZE 1 idlist id_next 12 6 Guide to Informix Enterprise Replication replicate attributes dummy variable freq tx s sent threshold in bytes primary method secondary method identifier next identifier Severe Error Table typedef struct q_type uintl qtype X Unused field only present for backward compatability char dbspace CDR_GL_NAMESIZE 1 dbspace for Q STABLE CDR_qtype typedef struct serv_attrs uint2 sflags definition flags uint2 idle connection time out minutes CDR_qtype sendq send queue type CDR_qtype recvq receive queue type char atsDir CDR_DIRNAMESIZE 1 ATS spool dir char risDir CDR_DIRNAMESIZE 1 RIS spool dir char syncServ CDR_GL_NAMESITZE 1 db server group to syn
153. e Conflict Resolution Rule The ignore conflict resolution rule does not attempt to detect or resolve conflicts A row or transaction applies successfully or it fails A row might fail to replicate because of standard database reasons or replication order errors The ignore conflict resolution rule can only be used as a primary conflict resolution rule and can have either a transaction or a row by row conflict resolution scope Figure 7 12 illustrates the ignore conflict resolution rule Figure 7 12 Ignore Conflict Resolution Rule Database Operation Row Exists in Target Insert Update Delete No Apply row Discard row Discard row Yes Discard row Apply row Apply row When a replication message fails to apply on a target you can spool the information to one or both of the following directories m Aborted transaction spooling ATS If selected all buffers in a failed replication message that compose a transaction are written to this directory m Row information spooling RIS If selected the replication message for a row that could not be applied to a target is written to this directory Using Cascading Deletes and Triggers Enterprise Replication supports cascading deletes and triggers that are defined on replicated tables The following information describes how Enter prise Replication processes cascading deletes and triggers on target database servers 7 20 Guide to Informix Enterprise Replication Confli
154. e INSERT statement and explicitly include the cdrserver and cdrtime columns in the list when you load your data For more information about the UNLOAD and LOAD statements see the Informix Guide to SQL Syntax Blocking Replication If the table that you are preparing for replication is in a database that already uses replication you might need to block replication while you prepare the table The BEGIN WORK WITHOUT REPLICATION statement starts a trans action that does not replicate to other database servers The following code fragment shows how you might use this statement BEGIN WORK WITHOUT REPLICATION LOCK TABLE office DELETE FROM office WHERE description portlandR_D COMMIT WORK The following list indicates actions that occur when a transaction starts with BEGIN WORK WITHOUT REPLICATION m All constraint checking for the transaction is automatically set to deferred m SQL does not generate any values for the shadow columns cdrserver and cdrtime for the rows that are inserted or updated within the transaction You must supply values for these columns with the explicit column list You must supply values for the shadow columns even if you want the column values to be NULL 6 6 Guide to Informix Enterprise Replication Blocking Replication m If you use the WITH CRCOLS clause to modify a table that is already defined in Enterprise Replication you must explicitly list the columns to be modified The following tw
155. e catalog with CDR_serv_attrs Severe Error Table The severe error table is a repository for remote errors that the user does not see at runtime The same information is available in the syscdrerror table in the sysmaster database Information Maintained in the Severe Error Table Suppose you define a replicate between servers g_serverl and g_server3 while connected to g_serverl The replicate definition will succeed on g_serverl even if the table specified in the SELECT statement is spelled differently on g_server3 than on g_serverl However the message log for server g_server3 will display an error message and an appropriate error is written into the severe error table API Functions 12 7 Enterprise Replication APIs a a a a Retrieving Information from the Severe Error Table The severe error table is replicated to all servers in the replication system so the information is available from any server in your replication environment However do not attempt to examine this table directly The syscdr database is reserved for internal use To examine the error information use the syscdrerror table of the sysmaster database To examine and manage the severe error table use the following tools m CLU option cdr error m API functions cdr_error_reviewed cdr_move_errortab cdr_prune_errors cdr_prune_single_error Enterprise Replication APIs The following table lists the API functions for Enterprise Repl
156. e replicated data to target database servers When Enterprise Replication applies replication messages it checks to make sure that no collisions exist A collision occurs when potential simultaneous updates of the same data on different database servers are applied Enter prise Replication reviews data one row at a time to detect a collision Enterprise Replication scans to see if the same primary key already exists in the target table or in the associated delete table or if a replication order error is detected A delete table stores the row images of deleted rows A replication order error is the result of a replication message that arrives from different database servers with one of the following illogical results m A replicated DELETE that finds no row to DELETE on the target m An UPDATE that finds no row to UPDATE on the target m An INSERT that finds a row that already exists on the target 7 12 Guide to Informix Enterprise Replication India Pakistan en ye EP field value field value K Bangkok field value Choosing Conflict Resolution Rules and Scopes If Enterprise Replication finds a collision it must resolve the conflict before it applies the replication message to the target database server Figure 7 9 Pakistan Collision Example Products in inventory ae Y a Column Column A a N N field value Mx Bangkok x t2227 Y Figure 7 9 shows a situation that yields a conflict Pakista
157. e root servers connected with LAN and a nonroot server connected over a modem The CDR_NIFCOMPRES configuration parameter is set so that connections between A B and C use no compression The connection from C to D uses level 6 Figure A 1 Database Servers with Different Compression Levels A 6 Guide to Informix Enterprise Replication CDR_NIFRETRY CDR_NIFRETRY default value 300 units seconds range of values any reasonable value takes effect when shared memory is initialized The CDR_NIFRETRY configuration parameter specifies the maximum time between retries when the database server is trying to make a connection for Enterprise Replication If the value is 0 the database server does not retry the connection The first retry happens after 15 seconds and the next after 30 seconds The retry interval keeps increasing doubling the previous retry interval until the CDR_NIFRETRY is reached Retry happens only if the connection goes down abnormally as in a power failure A graceful shutdown of a server does not cause a retry CDR_QUEUEM EM value 4096 units kilobytes range of values gt 500 takes effect when shared memory is initialized The CDR_QUEUEMEM configuration parameter specifies the maximum amount of memory that is used for the send and receive queues If your logical logs are large you can use CDR_QUEUEMEM to limit the amount of memory devoted to queues Configuration Parameters A 7 CDR_QUEUEM
158. e server However if the repli cation operation is a delete Enterprise Replication does not send BYTE or TEXT data to the target database server BYTE and TEXT data that is stored in blobspaces is not recorded in the logical log but the transaction itself is logged Such transactions can be replicated but the BYTE or TEXT data is retrieved from the blobspace itself at the time that Enterprise Replication is preparing to send the transaction to the target system Thus it is possible that the BYTE or TEXT data has been modified subsequent to the transaction currently being replicated If Enterprise Repli cation encounters BYTE or TEXT data that has been modified since the transaction currently being replicated it sends the data that it can success fully retrieve and flags the non retrievable BYTE or TEXT data as undeliverable However in most cases the action update that caused the BYTE or TEXT data to be modified is waiting to be delivered so the data again becomes consistent The data is inconsistent only in a small window of time Conflict Resolution for Simple Large Objects The following information explains how Enterprise Replication evaluates conflicts in an update anywhere replicate with a time stamp conflict resolution rule and a row by row conflict resolution scope When a replicated BYTE or TEXT column is modified on the source database server Enterprise Replication records cdrserver and cdrtime for that column For more in
159. e starts on all servers that are included in the replicate When a replicate starts on a server the participant on that server enters the active state data is captured and sent Thus a replicate can have both active and inactive participants When at least one participant is active the replicate is active If repl_name is a member of a replicate group this command fails Instead use the cdr start group command on page 11 66 Example The following command starts the replicate accounts on the server groups g_svrl and g_svr2 cdr start replicate accounts g_svrl g_svr2 Command Line Utility 11 67 cdr stop cdr stop The cdr stop command stops Enterprise Replication processing Syntax cdr stop p 11 6 Usage In most situations Enterprise Replication starts when cdr define server is first executed The replication threads remain running until the database server is shut down or until the local database server is deleted with the cdr delete server command If you shut down the database server while Enterprise Replication is running replication begins again when you restart the database server Under rare conditions users might want to temporarily stop the Enterprise Replication processing without stopping the database server The cdr stop command shuts down all Enterprise Replication threads in an orderly manner When the shutdown of Enterprise Replication is complete the message CDR shutdown complete appears
160. e to replicate daily at 1 00 A M cdr modify repl a 01 00 smile The following example modifies the frequency attributes of replicate smile to replicate on the last day of every month at 5 00 A M to generate ATS files and not to fire triggers cdr modify repl a L 5 00 A y T n smile The following example changes the mode of the first participant listed to read only and the mode of the second to primary If server1 needed to be taken for some reason you might want to make this type of change cdr mod repl smile R dbl serverl antonio tablel P db2 server2 carlo table2 11 58 Guide to Informix Enterprise Replication cdr modify server cdr modify server The cdr modify server command modifies the Enterprise Replication attributes of a database server Syntax cdr modify server 8 server_ group N Connect Option p 11 8 idle interval mode primary E readonly No 8 ats ats_dir _ o o o o oo ris ris_dir Element Purpose Restrictions ats_dir Name of aborted transaction Must be a full pathname Directory name on spooling directory your operating system interval Idle time out for this server Must be an integer gt 0 Integer number of 0 no timeout minutes ris_dir Name of the row information Must be a full pathname Directory name on spooling directory your operating system server_group Name of a server group to The server group must be Database server
161. ed Brick Data Mine Red Brick Mine Builder Red Brick Decisionscape Red Brick Ready Red Brick Systems Regency Support Rely on Red Brick RISQL Solution Design STARindex STARjoin M SuperView TARGETindex TARGETjoin The Data Warehouse Company The one with the smartest data wins The world is being digitized We re indexing it Universal Data Warehouse Blueprint Universal Database Components Universal Web Connect ViewPoint Visionary Web Integration Suite The Informix logo is registered with the United States Patent and Trademark Office The DataBlade logo is registered with the United States Patent and Trademark Office Documentation Team Linda Briscoe Mary Kraemer Jennifer Leland Judith Sherwood GOVERNMENT LICENSE RIGHTS Software and documentation acquired by or for the US Government are provided with rights as follows 1 if for civilian agency use with rights as restricted by vendor s standard license as prescribed in FAR 12 212 2 if for Dept of Defense use with rights as restricted by vendor s standard license unless superseded by a negotiated vendor license as prescribed in DFARS 227 7202 Any whole or partial reproduction of software or documentation marked with this legend must reproduce this legend Guide to Informix Enterprise Replication Table of Contents Introduction In This Introduction About This Manual Types of Users Softwa
162. ed for the product described The following items appear in the Informix folder To display this folder choose Start gt Programs gt Informix from the Task Bar Program Group Item Description Documentation Notes This item includes additions or corrections to manuals and information about features that might not be covered in the manuals or that were modified since publication Release Notes This item describes feature differences from earlier versions of Informix products and how these differ ences might affect current products This file also contains information about any known problems and their workarounds Machine notes do not apply to Windows environments Introduction 15 Related Reading Related Reading For a list of publications that provide an introduction to database servers and operating system platforms refer to your Getting Started manual Compliance with Industry Standards The American National Standards Institute ANSI has established a set of industry standards for SOL Informix SQL based products are fully compliant with SQL 92 Entry Level published as ANSI X3 135 1992 which is identical to ISO 9075 1992 In addition many features of Informix database servers comply with the SOL 92 Intermediate and Full Level and X Open SQL CAE common applications environment standards Informix Welcomes Your Comments Let us know what you like or dislike about our manuals To help us with futu
163. empt to sync with leaf server CDR_ESTOPFLAGS 87 Invalid cdr stop options 88 not in use CDR_EMODRECVO 89 Cannot modify dbspace for queues CDR_ECLOCKSKEW 90 System clocks are out of synchronization CDR_ESERVSTATE 91 Invalid server state transition CDR_ESERVERR 100 Fatal server error 5 of 6 C 6 Guide to Informix Enterprise Replication Definition of Return Codes Numeric Mnemonic Value Description struct CDR_ENOSUPPORT 01 Unsupported feature CDR_EINVSYNC 02 Root server cannot sync with nonroot or leaf servers CDR_EINVCONNECT 03 Invalid server to connect CDR_ETEMPDB 04 Cannot use temp dbspaces for Send Recv Queues This error also occurs if you try to move the Error Table into a temporary dbspace 6 of 6 Return Codes C 7 Fine Tuning Enterprise Replication This appendix provides reference material and several examples to help you fine tune Enterprise Replication Evaluating Images in a Complex Transaction Figure D 1 on page D 2 illustrates the evaluation compression of a single transaction with the following activities m One row is inserted and then updated several times m Another row ina different table is updated twice and the primary key changes in the second update Each row is evaluated against the appropriate replicates and a list of replicates is assembled where the row has been evaluated as a yes Evaluating Images in a Complex Transaction Figure D 1 How Enterprise Replica
164. end queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize transactions if a replicate is suspended For example a transaction that updates tables X and Y will be split if replication for table X is suspended 12 44 Guide to Informix Enterprise Replication cdr_suspend_repl cdr_suspend_repl The cdr_suspend_repl function suspends delivery of data from a replicate Syntax include cdrapi h int cdr_suspend_repl repl time char repl time_t time not used repl is the replicate name time is not used but cannot be omitted Use time_t 0 for that argument Usage The replicate repl enters the suspend state that is do not capture or send repli cation data for all participants If repl is contained in a replicate group the call fails To suspend replication on a replicate group see cdr_suspend_group on page 12 44 Warning When a replicate is suspended Enterprise Replication holds the replication data in the send queue until the group is resumed If lots of data is generated for this replicate while it is suspended the send queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize transactions if a replicate is suspended For example a transaction that updates tables X and Y will be split if replication for table X is suspended API Functions 12 45 cdr_suspend_serv cdr_suspend_serv T
165. eplicate WHERE clause column update A row that does not meet the WHERE clause selection criteria is updated to meet the criteria Enterprise Replication replicates the updated row image and converts the update to an insert Evaluating Primary Key Updates Enterprise Replication evaluates rows for primary key updates for WHERE clause column updates and for multiple updates to the same row The following list describes an occurrence in a transaction and the Enterprise Replication action m Primary key updates Enterprise Replication translates an update of a primary key into a delete of the original row and an insert of the row image with the new primary key If triggers are enabled on the target system insert triggers are executed m Multiple row images in a transaction Enterprise Replication compresses multiple row images and only sends the net change to the target Triggers execute only once m WHERE clause column updates If a replicate includes a WHERE clause in its data selection the WHERE clause imposes selection criteria for rows in the replicated table a Ifan update changes a row so that it no longer passes the selection criteria on the source it is deleted from the target table Enterprise Replication translates the update into a delete and sends it to the target o Ifan update changes a row so that it passes the selection criteria on the source it is inserted into the target table Enterprise Repli cation translates
166. eplication Defining a Replicate Group To define a replicate group choose Group Define Group The Group Define Group menu item starts the Define Replicate Group wizard The wizard describes the steps needed to define a replicate group and then provides a series of pages that guide you through the process Enterprise Replication Manager Wizards 9 15 Choosing a Group Name Choosing a Group Name In Figure 9 10 on page 9 16 the wizard asks you to choose a name for the replicate group and to specify whether or not to apply the replicated data sequentially For information about sequential data application refer to Replicate Group on page 2 12 Define Replicate Group Wizard Figure 9 10 El Define Replicate Group Name Choosing the Replication Interval for the Group Next the wizard asks you to choose a replication interval for your replicate group The display for specifying the replication interval for the group is the same as the display for specifying the replication interval for a replicate as shown in Figure 9 4 on page 9 7 Important Each replicate in a replicate group must have the same time based repli cation frequency value or all replicates must have continuous replication 9 16 Guide to Informix Enterprise Replication Selecting Replicates for the Replicate Group Selecting Replicates for the Replicate Group The Define Replicate Group wizard page in Figure 9 11 asks you to select the
167. eplication cdr_define_serv The attrs argument specifies attributes for the database server To specify attributes set the appropriate flag bit in attrs sflags and use the supplied structure member as the following table shows Attribute A_ATS A_IDLE A_INIT A_LEAF A_NONROOT A_RECVQ A_ROOT A_RIS A_SENDQ A_SYNC Description Use attrs ats_dir as the directory for ATS files For more infor mation see Chapter 10 All database servers maintain a separate connection to all other database servers participating in replication exclusively for the transmission of replication data Because the connection consumes system resources an idle time out provides a way to optimize infrequent connections The connection will be automat ically re established when data is queued for the database server The idle time out is specified in minutes by attrs timeout Enterprise Replication is initialized on the database server that is defined Define this replication server as a leaf server A_ROOT A_NONROOT and A_LEAF are mutually exclusive Define this replication server as a nonroot server Use attrs recvq for the receive queue dbspace The receive queues is assigned to a particular dbspace The receive queue dbspace cannot be a temporary dbspace The path for the receive queue dbspace must be no longer than 128 bytes Define this replication server as a root server Use attrs ris_dir as the directory for RIS files
168. ery of replication data for replicates defined in a replicate group Syntax repl_ group cdr resume group p 11 8 Element Purpose Restrictions Syntax repl_group Name of replicate group to The group must be suspended Identifiers p 8 8 resume Usage The cdr resume group command causes all replicates contained in the replicate group repl_group to enter the active state for all participants For more information about replication states refer to Changing Replicate States on page 8 14 Example The following example connects to the default database server INFORMIXSERVER and resumes the replicate group accounts cdr resume group accounts Command Line Utility 11 61 cdr resume replicate cdr resume replicate The cdr resume replicate command resumes delivery of replication data Syntax cdr resume replicate repl_ name p 11 8 Element Purpose Restrictions Syntax repl_name Name of the replicate to change The replicate must not be a Identifiers p 8 7 to active state member of a replicate group and must be suspended Usage The cdr resume replicate command causes all participants in the replicate repl_name to enter the active state If the replicate repl_name is a member of a replicate group this command fails When repl_name is in a replicate group use the cdr resume group command on page 11 61 For more information on replicate states refer to Changing
169. es the problem The messages are documented in Appendix C Three Context Message examples follow define replicate repl_1 database does not exist start group accounts illegal group state change suspend server lake insufficient memory to perform operation 10 14 Guide to Informix Enterprise Replication Command Line Utility ln This Chapter tulo a Ge el a als ala OTS List of Commands M5 Command Line Abbreviations H 6 Option Abbreviations 11 6 Order of the Options 2 2 2 11 7 Backslash Use ee ee ee ee 18 Connect Option 2 2 2 a ee 18 Participant ae ae eed Ke tt ae e ES Using the O and I Options dr a a ds e MO Using the P and R Options 11 10 Participant Modifier cias 2 eh aoe A Restrictions on the SELECT Statement 2 oa a e MEA Database Server Groups 2 og aygan e ye a E Server Groups on UNIX a a aaa a 1 12 Server Groups on WindowsNT aaa 1113 Return Codes 2 we eee 1113 Frequency Options a a ee 114 Time of Day 25 2 H AO Ae AA ara Intervals 2 we eoa ww 1 16 Example Using the Command Line Utility 11 16 Command Line Utility Syntax 2 ew we 11 19 cdr change group ee ee ee ee 1 20 cdr change replicate 0 ee ee ee 11 22 cdr connect
170. ethod selected is time stamp The only valid bit is STORED_PROCEDURE A_RSCOPE Activates conflict resolution on a row by row basis This is mutually exclusive with A_TSCOPE A_TSCOPE Activates conflict resolution on a transaction basis This is mutually exclusive with A_RSCOPE A_RIS Activates row information spooling for replicate row data that fails conflict resolution or encounters repli cation order problems For more information see Row Information Spooling on page 10 9 A_ATS Activates aborted transaction spooling for replicate transactions that fail to be applied to the target database For more information see Aborted Trans action Spooling on page 10 3 1 of 2 API Functions 12 15 cdr_define_reol Flags Field Macros Type of Value Data format Trigger activation Frequency specification Owner value for permission checking A_CANONICAL A_TRIGGER A_FREQ A_USETABOWNER Description All replication data for the replicate is delivered in machine independent form This machine independent format is required for replicates defined over a heterogeneous collection of database servers where the replication data is of type float or double Triggers should be fired for this replicate The default fires no triggers for replicated updates Sets the frequency of data replication to the interval specified by attrs freq See the A_BEGIN flag bit for discussion of time zones The defaul
171. ewing Replicate Properties on page 8 17 Figure 9 3 Replicate Options Wizard Page Define Replicate Wizard 9 6 Guide to Informix Enterprise Replication Selecting the Replication Frequency Selecting the Replication Frequency Next the wizard asks you to specify whether you want replication to be continuous or time based In the example in Figure 9 4 time based replication will occur every Sunday at 3 45 P M Figure 9 4 Select Frequency Page Define Replicate Wizard LN E Enterprise Replication Manager Wizards 9 7 Selecting the Replication Frequency With the time based option you can choose the time in hours and minutes and day day of week day of month that data replication occurs in a replicate Time based replication begins when you start the replicate The following table summarizes the options you can select to determine when replication occurs Value Description Continuous This value is the default Enterprise Replication sends changes that should be replicated as soon as it detects them Time based Replicate data at a specified interval using the Every option or at a specific time on a specific day using the At option Day of the week Replicate data once a week at the time and day specified You can also replicate data at the same time each day of the week by selecting the value Dai y in the Day of the week text box Day of the month Replicate data once a month at the specifie
172. example cannot retrieve replicate id for the replicated row unable to determine the replicated column s type size or length it displays this row data in hexadecimal format 10 10 Guide to Informix Enterprise Replication BYTE and TEXT Information in RIS Files BYTE and TEXT Information in RIS Files When the information recorded in the RIS file includes BYTE or TEXT data the RRD information is reported as the following examples show Example 1 lt 1200 TEXT PB 877 necromsv 840338515 96 08 17 20 21 55 gt where m 1200 is the size of the TEXT data m TEXT is the data type it is either BYTE or TEXT m PB is the storage type PB for storage in the tablespace BB for blobspace storage m The next two fields are the server identifier and the time stamp for the column if the conflict resolution rule is defined for this replicate and the column is stored in a blobspace Diagnosing Enterprise Replication 10 11 BYTE and TEXT Information in RIS Files Example 2 from the source server RRH Row 1 Collection Id 24707077 Repl tores cdr item DbOp Update H CDR 14 Failed conflict resolution rul S pur1 392 96 05 29 23 27 20 833437640 S R R R R 0 RRS s1s4 390 96 05 29 23 26 18 833437578 R 0 R H Row 2 Collection Id 24707077 Repl tores cdr item DbOp Update RH CDR 14 Failed conflict resolution rul RS pur1 392 96 05 29 23 26 52 833437612 RD 10 Digitizer 319 A Apple Toyota Digiti
173. f Trees A forest of trees consists of several hierarchical trees whose root database servers are fully connected Each hierarchical tree starts with a root database server The root database servers transfer replication messages to the other root servers for delivery to its child database servers Figure 2 4 shows a forest of trees Figure 2 4 O America France Forest of Trees Topology A gt lt Germany Asia Ss China O a Beijing DN Guangzhou Hong Kong In Figure 2 4 North America Asia and Europe are root database servers That is they are fully connected with each other France and Germany are in a tree whose root is Europe Asia is the root for the six database servers in its tree Ina forest of trees all replication messages from one tree to another must pass through their roots For example a replication message from Beijing to France must pass through China Asia and Europe Enterprise Replication Features 2 7 Enterprise Replication Objects Organizing the database servers in a hierarchical tree or a forest of trees greatly reduces the number of physical connections that are required to make a replication system If all the database servers in Figure 2 4 were fully connected instead of being organized in trees 55 connections would be required Enterprise Replication Objects Enterprise Replication defines many objects that define the data in a repli cation system and how it is treated T
174. file m not a shared memory connection CDR_ECDR 63 Enterprise Replication already active The database server that you tried to define is already active in Enterprise Replication CDR_ENOSYNC 64 Remote cyclic synchronization not allowed CDR_ESERVID 65 Server identifier already in use CDR_ENOTIME 66 No upper time for prune error CDR_ERRNOTFOUND 67 Error not found for delete or update CDR_EPARTMODE 68 Illegal participant mode CDR_ECONFLICT 69 Conflict mode for replicate not ignore CDR_ECONSAME 70 Connect disconnect to from same server CDR_EROOT 71 Conflicting root server flags CDR_EPARENT 72 Cannot delete server with children 4 of 6 Return Codes C 5 Definition of Return Codes Numeric Mnemonic Value Description struct CDR_ESPAROOT 73 Leaf root configuration not allowed 74 not in use CDR_ELIMITED 15 Request denied on limited server CDR_EMSGFORMAT 76 Unsupported message format CDR_EDROPDB 77 Could not drop syscdr database CDR_EATSDIR 78 ATS directory does not exist CDR_ERISDIR 79 RIS directory does not exist CDR_ECRCHANGE 80 Illegal conflict resolution change CDR_EUDTBADCOL 81 UDT collection types not allowed CDR_EUDTEXPR 82 UDTs not allowed in expressions such as where clauses CDR_ENOUDTPKEY 83 No UDTs in primary key allowed The primary key for a replicated table cannot contain UDTs CDR_ESYNC 84 No sync server with nonroot and leaf CDR_EPARTFLAGS 85 Incorrect participant flags CDR_ELEAF 86 Conflicting leaf server flags or att
175. fined as a root server Uses the global catalog on sync_server as the template for the global catalog on the new replication server server_group The cdr define server command enters a database server from the server_group into the Enterprise Replication global catalog Element ats_dir recu_space ris_dir send_space timeout Options The options allow you to modify the default behavior of cdr define server Options Purpose Name of the directory for aborted transaction spooling Name of the dbspace for the receive queue Name of the directory for row information spooling Name of the dbspace for the send queue Idle timeout for this replication server cdr define server Back to cdr define server p 11 33 send send_ space recv recv_ space ats ats_dir ris ris_ dir idle timeout Restrictions Must be a full pathname The path for the directory can be no longer than 256 bytes The dbspace must already exist The path for the receive queue can be no longer than 128 bytes The recv_space cannot be a temporary dbspace Must be a full pathname The path for the directory can be no longer than 256 characters The dbspace must already exist The path for the send queue can be no longer than 128 bytes The send_space cannot be a temporary dbspace Must be an integer number of minutes 0 indicates no timeout The maximum value is 32 kilobytes 0 indicates no timeout
176. fines a replicate group that includes the replicates listed in repls The replicates specified must be defined over the same set of replication database servers and must all be in the same repli cation state Any valid replicate can be defined as part of a replicate group providing the participant list is identical The group name must be no longer than 128 bytes and must start with a letter or an underscore All replicates must be in the same replication state That is all replicates must be active or all replicates must be inactive API Functions 12 11 cdr_define_group Flag Value A_NONSEQUENTIAL frequency structure Flag Value FREQ _IMMED FREQ INTERVAL FREQ TIME FREQ DAYOFWEEK FREQ _DAYOFMONTH 12 12 Guide to Informix Enterprise Replication The attrs argument specifies attributes for the replicate group The following attributes specify how the system processes data for the replicate group To specify the attributes set the appropriate flag bit in attrs Description This option configures Enterprise Replication to process all nonsequential groups in parallel Use this option only when groups have disjoint data domains The default is sequential processing of groups The freq argument specifies the frequency with which data is replicated to database servers that participate in the replicate group This defaults to the frequency of the participating replicates if the argument is null The following frequen
177. first participant db1 iowa antonio tablel with the select statement select from tablel Line 4 defines a second participant db2 utah carlo table2 with the select statement select from table2 Command Line Utility 11 31 car define replicate The next example is the same as the preceding example with the following exceptions Line 1 instructs Enterprise Replication to use the global catalog on database server ohio Line 2 also specifies that the data should be replicated every five hours 1 cdr def repl c ohio C timestamp spl 2 S tran A e 5 00 newrepl Y 3 dbl iowa antonio tablel select from tablel A 4 db2 utah carlo table2 select from table2 The following example is the same as the preceding example except data will be replicated daily at 1 00 A M cdr define repl c ohio C timestamp spl s tran A a 1 00 replname Y dbl iowa antonio tablel select from tablel Y db2 utah carlo table2 select from table2 The following example is the same as the preceding example except data will be replicated on the last day of every month at 5 00 A M cdr define repl c ohio C timestamp spl Y S tran A a L 5 00 replname A dbl iowa antonio tablel select from table Y db2 utah carlo table2 select from table2 11 32 Guide to Informix Enterprise Replication cdr define server cdr define server The cdr define
178. for Primary Target Replication Ot Blige gee AANS 4 8 Administering the Replication System 4 8 Planning for Capacity 2 ee ee 4 8 Planning for High Availability 2 we 4 8 Update Anywhere Replication ae Ge OF afl Hier fo a BS 4 9 Facts to Consider ts al do geal ae Gy poe ae 4 9 Chapter 5 Setting Up Your Replication Environment In ThisChapter 33 gt oi o ge ai at Se ae Rpt a hws Se 5 3 Operational Limitations 2 ee ee 5 3 SOL Statement Use a uses is a Ee ae 5 3 Forbidden SQL Statements E de tc Lope Be de da By ae ce e 5 4 Limited SQL Statements a a o 5 4 Permitted SQL Statements 2 2 44 5 4 Capacity Planning ee 5 5 Logical Log Records 0 ee ee ee 5 5 Send and Receive Message Queues 5 6 Delete Tables s 2 ee ee 5 7 Spooling Directories 2 2 2 1 1 ee ee ee 5 7 Configuration Parameters 2 1 ee es 5 8 Enterprise Replication Threads 1 1 we 5 8 Environmental Considerations 5 9 Time Synchronization 2 1 we ee 5 9 Transaction Processing Effect 5 10 Enterprise Replication Data Types pa ee de eye BELT Replicating on Heterogeneous Hardware E o en ee ae A Replicating Simple Large Objects 3 1 Replicating User Defined Data Types 5 15 Replicating Smart Large Objects 5 15 Usi
179. formation on cdrserver and cdrtime see Shadow Columns on page 6 4 If the BYTE or TEXT column on the target database server is also stored in a blobspace Enterprise Replication evaluates the cdrserver and cdrtime values in the source and target columns and uses the following logic to determine if the data is to be applied 1 If the column of the replicated data has a time stamp that is greater than the time stamp of the column on the local row the data for the column is accepted for replication 2 Ifthe server ID and time stamp of the replicated column are equal to the server ID and time stamp on the column on the local row the data for the column is accepted for replication 5 12 Guide to Informix Enterprise Replication Replicating Simple Large Objects If either condition is true the data for the column is accepted for replication even if the rest of the data that is neither BYTE nor TEXT is rejected This can occur in certain situations where transactions arrive out of order Evaluating BYTE and TEXT Data with SPL Procedures If the replicate is defined with a stored procedure conflict resolution rule the procedure must return the desired action for each BYTE or TEXT column When the procedure is invoked information about each BYTE or TEXT column is passed to the procedure as five separate fields The following table describes the fields Argument Description Column size INTEGER NULL if the column is NULL
180. function modifies the attributes of a replicate group Syntax include cdrapi h int cdr_modify_group group attrs freq char group uint4 attrs CDR_freq freq group is the replicate group name attrs are the replicate group attributes freq are the frequency attributes Usage The cdr_modify_group function modifies the group group with attributes attrs The attrs argument specifies which attributes to modify For a description of the attributes see cdr_define_group on page 12 11 The freq argument can be null in such cases the frequency attributes of the replicate group are not modified You cannot remove replicates from a group when the group is suspended Also you cannot add a suspended replicate to a group even if the replicate group is also suspended To add or remove replicates from a replicate group use cdr_participate_group on page 12 31 12 24 Guide to Informix Enterprise Replication cdr_modify_repl cdr_modify_repl The cdr_modify_repl function modifies replicate attributes Syntax include cdrapi h int cdr_modify_repl repl_name attrs char repl CDR_repl_attrs attrs repl_name is the replicate name attrs are the frequency attributes Usage The cdr_modify_repl function modifies the replicate rep with the replicate attributes attrs The attrs argument specifies the new attributes for the replicate For the definition of the CDR_repl_attrs
181. g the boston Nonroot Server Defining the denver Nonroot Server Defining a Leaf Replication Server Displaying the Hierarchy Viewing the Server Properties 3 2 Guide to Informix Enterprise Replication In This Chapter This chapter contains simple examples of replication The first three examples use the command line utility CLU that allows you to control Enter prise Replication from the command line Chapter 11 Command Line Utility documents the CLU The second three examples use the Enterprise Replication Manager ERM a graphical user interface GUI that runs on Windows NT to perform the same replications as the first three examples Chapter 8 Enterprise Replication Menus and Chapter 9 Enterprise Replication Manager Wizards document ERM Environment for the Replication Examples To run the replication examples in this chapter you need three Informix database servers Each database server must be in a database server group This example uses the following environment m Three UNIX computers s1 s2 and s3 are hosts for the database servers usa italy and japan respectively Each computer has active network connections to the other two computers m The database servers usa italy and japan are members of the database server groups g_usa g_italy and g_japan respectively For information about database server groups see Database Server Groups on page 12 3 Replication Examples 3 3
182. group 11 70 cdr stop replicate 11 71 cdr suspend group 11 73 cdr suspend replicate 11 75 cdr suspend server 11 77 2 of 2 Command Line Abbreviations Each of the words that make up a cdr command variation can be abbreviated to three or more characters For example the following commands are all equivalent cdr define replicate cdr define repl cdr def rep Option Abbreviations Each option for a command has a long form and a short form You can use either form and you can mix long and short forms within a single command For example using long forms you can write cdr define server connect ohio idle 500 send dbsl recv dbs2 ats cdr ats initial utah Using short forms you can write the previous example as follows cdr def ser c ohio i 500 s dbsl r dbs2 A cdr ats I utah 11 6 Guide to Informix Enterprise Replication Order of the Options The long form is always preceded by a double minus Most but not all long forms require an equals sign between the option and its argument The short form is preceded by a single minus and is the first letter of the long form The short form never requires an equals sign However sometimes the short form is capitalized and sometimes not To find the correct syntax for the short form check the table that accompanies each command variation Tip Informix suggests that you use the long forms of options when you are preparing a script that might
183. groups are the database server names prefixed by g_ The g_ prefix is not a requirement it is just the convention that this manual uses Leave the Class dialog box blank Click OK E 4 Guide to Informix Enterprise Replication Preparing the SOLHOSTS Connectivity Information Select the new key that you just made the key with the database server group name Choose Edit gt Add Value In the Add Value dialog box enter one of the fields of the sqlhosts information HOST OPTIONS PROTOCOL SERVICE in the Value Name dialog box Do not change the Data Type dialog box Click OK In the String Editor dialog box type the value for the field that you selected and click OK For a database server group enter the following values HOST OPTIONS i unique integer value PROTOCOL group SERVICE gt Each database server group must have an associated identifier value i that is unique among all database servers in your environment Enter a minus for HOST and SERVICE to indicate that you are not assigning specific values to those fields Repeat steps 6 and 7 for each field of the sqlhosts information Exit from the Registry Editor SQLHOSTS Registry Key E 5 Enterprise Replication onstat g Options This appendix describes forms of the onstat command that are relevant to Enterprise Replication The onstat utility reads shared memory structures and provides statistics about the database server that are accurate at the i
184. hapter 9 Chapter 10 Chapter 11 Chapter 12 Enterprise Replication Processes Enterprise Replication Menus Enterprise Replication Manager Wizards Diagnosing Enterprise Replication Command Line Utility API Functions Enterprise Replication Processes In This Chapter Capturing Transactions Evaluating Data for Replication Evaluating Time Evaluating Images of a Row Evaluating Replication Examples Evaluating Primary Key Updates Receiving and Sending Data from the Nesas ins Applying Data for Distribution Choosing Conflict Resolution Rules and Scopes Time Stamp Conflict Resolution Rule Stored Procedure Conflict Resolution Rule Ignore Conflict Resolution Rule Using Cascading Deletes and Triggers Using Cascading Deletes Using Triggers 7 3 73 7 4 7 4 7 5 7 7 7 10 7 11 7 12 7 13 7 15 7 17 7 20 7 20 7 21 7 21 7 2 Guide to Informix Enterprise Replication In This Chapter Enterprise Replication uses various processes to gather and replicate data This chapter discusses the processes that replicate data after you define your replication system m Capturing transactions m Evaluating data for replication m Distributing replication messages Capturing Transactions As the replication server writes rows to the logical log it marks rows that should be replicated Later Enterprise Replication reads the logical log to obtain the row images for tables that participate
185. he Enterprise Replication objects are Enterprise Replication server Replicate Participant Replicate group Catalog For information about defining replication objects refer to Chapter 8 Enter prise Replication Menus and Chapter 11 Command Line Utility Enterprise Replication Server An Enterprise Replication server or replication server is an Informix database server that participates in data replication The replication server maintains information about the replication environment which columns should be replicated and the conditions under which the data should be replicated This information is stored in a database syscdr that the database server creates when it is defined as a replication server Multiple database servers can be on the same physical computer and each database server can partic ipate in Enterprise Replication 2 8 Guide to Informix Enterprise Replication Replicate Replicate A replicate defines the data database table and columns to be replicated and lists the database servers to which the data replicates In addition to its name a replicate contains the following information Replication options Replicate state Conflict resolution rules and scope Participants Replicate Options When you create a replicate you can specify the following options Aborted transaction spooling ATS Row information spooling RIS Canonical message format Database triggers for replica
186. he cdr_start_group function causes the replicates defined in the replicate group group to enter the active state capture send on the database servers in the servers list If the servers list is null then the specified replicate group enters the active state on all database servers API Functions 12 39 cdr_start_repl cdr_start_repl The cdr_start_repl function starts the capture and transmittal of data from a replicate Syntax include cdrapi h int cdr_start_repl rep servers time which char repl CDR_idlist servers time_t time void which repl is the replicate name servers is an optional list of database server groups for which replication should begin time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage The cdr_start_repl function causes the replicate rep to enter the active state data is captured and sent on the database servers in servers list If the servers list is null then the specified replicates enter the active state on all database servers To enter the active state m synchronize active participants m begin to capture data for replication on the participants specified If repl is contained in a replicate group the call fails To start replication on a group see cdr_start_group on page 12 39
187. he cdr_suspend_serv function suspends the delivery of replication data to a database server Syntax include cdrapi h int cdr_suspend_serv server servers time which char server CDR_idlist servers time_t time not used void which server is the database server name to suspend servers is an optional list of database server groups that include the database servers on which to suspend replication time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage The cdr_suspend_serv function suspends delivery of replication data to the database server specified by server from all database servers specified by the servers list Replication data continues to flow for all other database servers If the servers list is null delivery of replication data is suspended for all database servers None of the replication servers will send data to the suspended server Tip Unlike cdr_suspend_repl the replicate and or replicate group status is irrelevant 12 46 Guide to Informix Enterprise Replication Example Example In the following example the five database server groups are g_s1 through g_s5 The database server s1 is the synchronization server cdr_connect sl could be any of the five servers cdr_suspend_serv g_s3 g_sl g_s2 g_s4 g_s5 time_t 0 err
188. hema CREATE DATABASE general WITH LOG or OPEN database general if already created CREATE TABLE employees emp_num INT empname CHAR 15 company CHAR 20 addressl CHAR 20 address2 CHAR 20 city CHAR 15 state CHAR 2 zipcode CHAR 5 phone CHAR 18 PRIMARY KEY emp_num WITH CRCOLS LOCK MODE ROW Step 1 Define Database Schema for Maine Site On the database server in Bangor Maine create database general Step 2 Define Database Schema for lowa Site On the database server in Ames Iowa create database general D 6 Guide to Informix Enterprise Replication Step 3 Define Database Schema for California Site Step 3 Define Database Schema for California Site On the database server in Milpitas California create database general Step 4 Declare Database Servers to Enterprise Replication Declare all three database servers bangor ames and milpitas to Enterprise Replication This step is required because none of the database servers has been previously declared You can declare the database servers using any of the following methods m Using the Enterprise Replication Manager m Using the CLU command cdr define server m Using the API call cdr_define_serv After the database servers are declared to Enterprise Replication each database server has a database named syscdr that contains the global catalog Step 5 Define a Replicate Called employeeinfo Next the replication system is
189. his replication Select g_italy and click Add Then select g_usa click Add and then click Next Figure 3 13 Select Servers for the Replicate g_italy 3 28 Guide to Informix Enterprise Replication Creating the Primary Target Replicate Selecting the Primary Enterprise Replication replicates changes from the primary participant to the secondary participant On the wizard page in Figure 3 14 on page 3 29 make sure that you select the Yes option button In the list box select g_usa and click Next Figure 3 14 Select the Primary Participant Replication Examples 3 29 Creating the Primary Target Replicate Selecting a Table The wizard page in Figure 3 15 lets you select the table to replicate Enter the name of the database the table owner the login name you used when you created the table and the name of the table Click Next Figure 3 15 Select a Table for Replication informix call_typ el 3 30 Guide to Informix Enterprise Replication Creating the Primary Target Replicate Selecting the Columns The wizard page in Figure 3 16 lets you specify which columns of the table should be replicated The SELECT statement causes all columns of the call_type table to be replicated There is no WHERE clause so all changes to call_type will be replicated Click Finish Figure 3 16 Prepare Select Statement Replication Examples 3 31 Creating the Primary Target Replicate Su
190. host2 g_svr2 informix customer select from customer command failed No conflict resolution rule specified 58 Command Line Utility 11 13 Frequency Options Frequency Options The following CLU options allow you to specify the interval between replica tions or the time of day when an action should occur If you do not specify a time the action occurs immediately cdr define group cdr define replicate cdr modify group cdr modify replicate Frequency Options immed every interval at time Element Purpose Restrictions Syntax interval Time interval for replication The smallest interval is minutes Intervals p 11 16 time Specific time for replication Time is given with respect toa 24 Time of Day hour clock p 11 15 The time options have the meanings that the following table shows Time Options Long Form Short Form Meaning immed i Action occurs immediately every e Action occurs immediately and repeats at the frequency specified by interval at a Action occurs at the specified day and time 11 14 Guide to Informix Enterprise Replication Frequency Options Time of Day The time of day is always given with respect to a 24 hour clock For example 19 30 is 7 30 P M Times are always given with respect to the local time unless the TZ environment variable is set However Enterprise Replication stores times in the global catalog in Greenwich mean time GMT Th
191. iami cdr delete server server_group_name cdr delete server c server_group_name server_group_name Defining the Nonroot Replication Servers Nonroot replication servers are continuously connected to their parent servers but are not connected to the other root servers Replication Examples 3 49 Defining a Leaf Replication Server Defining the boston Nonroot Server To add boston as a nonroot replication server select boston from the Server list box see Figure 3 9 on page 3 24 When ERM asks if you want to define boston as a replication server click Yes On the Declare Server wizard page select Nonroot Server in the Server Type dialog box Select g boston in the Parent Server dialog box Leave the other values set to their defaults If you want to view the completed wizard page see Figure 3 6 on page 3 22 Click OK Defining the denver Nonroot Server Follow the procedure in the previous section to declare denver as a nonroot replication server Defining a Leaf Replication Server A leaf server might have either a root or nonroot server as its parent A leaf server cannot be the parent of another replication server To add miami as a leaf server select miami from the Server list box When ERM asks if you want to define miami as a replication server click Yes On the Declare Server wizard page select Leaf Server in the Server Type dialog box Select g_usa in the Parent Server dialog box Leave the other values set to
192. icate Group Properties Replicate Group Properties You can use this dialog box to change the frequency of replication To change the frequency value click the Frequency tab change the frequency value and then click Apply 8 24 Guide to Informix Enterprise Replication Server Menu Server Menu Use the Server menu to manage the database servers that you have declared to Enterprise Replication The Server menu has the following options Suspend Server Resume Server Change State expert mode only Hierarchical Routing expert mode only Change to Primary Change to Target expert mode only Start Replication Stop Replication Use Table Owner Use Informix Remove Server Reload from Global Catalog Server Properties Suspending and Resuming a Database Server To suspend a database server select the database server and choose Server gt Suspend Server Suspend Server suspends the delivery of repli cation to a database server To resume a database server from the Server menu select the database server and choose Server gt Resume Server Resume Server resumes the delivery of replication to a database server To suspend or resume a server using the CLU refer to cdr suspend server on page 11 77 and cdr resume server on page 11 63 Enterprise Replication Menus 8 25 Finding or Changing the Server State Finding or Changing the Server State El Important This option is available only in expe
193. icate are inactive Figure 3 33 Inactive Participants et Replication Manager g japan g_italy Inactive E g_japan Inactive fe g_usa Inactive Follow the procedure described in Activating the Replicate on page 3 34 to activate all participants in repl4 3 48 Guide to Informix Enterprise Replication Cause a Replication Cause a Replication You can now modify the state table and observe the replication For example to insert a line into the state table on usa you can use DB Access as follows INSERT INTO stores usa state VALUES AT Atlantis Observe the change on the italy and japan database servers SELECT from storesQitaly state SELECT from stores japan state To insert a line into the state table on japan use DB Access as follows INSERT INTO stores japan state VALUES BR Brigadoon Verify that the new line was replicated to usa and italy Hierarchy Example Using ERM This example uses ERM to add a replication tree to the fully connected environment of the usa italy and japan replication servers Figure 3 1 on page 3 13 shows the hierarchy that this example will build Deleting the Previously Defined Servers If you did not delete the denver boston and miami servers in Removing Previously Defined Replication Servers on page 3 17 you must delete them now For each server issue the following command where server_group_name is g denver g boston or g m
194. icate to change The replicate must exist Identifiers p 8 8 The options in cdr change replicate have the meanings that the following table shows Options Long Form Short Form Meaning add a Add participant s to a replicate delete d Remove participant s from a replicate Usage Use this command to add or delete a participant from a replicate You can define a replicate that has zero or one participants but to be useful a replicate must have at least two participants 11 22 Guide to Informix Enterprise Replication car change replicate To add or delete a participant using ERM refer to Managing Replicates and Participants on page 8 13 Examples The following example adds two participants to the replicate named repl_1 db1 server1 antonio table with the modifier select from tablel and db20server2 carlo table2 with the modifier select from table2 cdr change repl a repl_1 dbl serverl antonio tablel select from tablel db2 server2 carlo table2 select from table2 The following example removes the same two participants from replicate repl_1 cdr change repl d repl_1 dbl serverl antonio tablel Y db20server2 carlo table2 Command Line Utility 11 23 cdr connect server cdr connect server The cdr connect server command re establishes a connection to a database server that has been disconnected with a cdr disconnect server command Syntax cdr
195. ication API Page cdr_connect 12 10 cdr_define_group 12 11 cdr_define_repl 12 14 cdr_define_serv 12 18 cdr_delete_group 12 20 cdr_delete_repl 12 21 cdr_delete_serv 12 22 cdr_error_reviewed 12 23 cdr_modify_group 12 24 1 of 2 12 8 Guide to Informix Enterprise Replication Enterprise Replication APIs API Page cdr_modify_repl 12 25 cdr_modify_replmode 12 27 cdr_modify_serv 12 28 cdr_modify_servmode 12 29 cdr_move_errortab 12 30 cdr_participate_group 12 31 cdr_participate_repl 12 32 cdr_prune_errors 12 33 cdr_prune_single_error 12 34 cdr_resume_group 12 35 cdr_resume_repl 12 36 cdr_resume_serv 12 37 cdr_start_cdr 12 38 cdr_start_group 12 39 cdr_start_repl 12 40 cdr_stop_cdr 12 41 cdr_stop_group 12 42 cdr_stop_repl 12 43 cdr_suspend_group 12 44 cdr_suspend_repl 12 45 cdr_suspend_serv 12 46 2 of 2 API Functions 12 9 cdr_connect cdr_connect The cdr_connect function designates the origin for control and configuration Important If you plan to call programs in addition to Enterprise Replication you must manage your own connections Syntax include cdrapi h int cdr_connect dbserver char dbserver dbserver is the name of the replication database server Usage The cdr_connect function specifies the database ser
196. ication 2 of 2 Columns of the Buffer Tables The tables whose names end with _buf give information about the buffers that form the transactions listed in the _txn table All the _buf tables have the same columns and the same column definitions Description Internal flags for this buffer Size of this buffer in bytes Server ID of the database server where this data originated This server ID is group ID from the sqlhosts file or the SQLHOSTS registry key Login ID of the user who originated the transaction represented by this buffer Log position on the source server for the transaction represented by this buffer 1 of 2 SMI Tables for Enterprise Replication Column Type Description cbkeysequence integer Sequence number for this buffer within the transaction cbgroupid integer Replicate or replicate group identifier for the data in this buffer cbcommittime integer Time when the transaction represented by this buffer was committed 2 of 2 The following columns combine to form the primary key for this table cbkeyserverid cbkeyid cbkeypos cbkeysequence The columns cbkeyserverid cbkeyid and cbkeypos form a foreign key that points to the transaction in the _txn table that the buffer represents SMI Tables for Enterprise Replication The following sections describe the individual tables of the sysmaster database that refer to Enterprise Replication syscdrack_buf The syscdrack_buf table contains inf
197. ime and have an accuracy of plus or minus one second Important Enterprise Replication does not manage clock synchronization between database servers that participate in a replicate To synchronize the time on one database server with the time on another database server use one of the following commands rdate hostname net time servername set 7 16 Guide to Informix Enterprise Replication Time Stamp Conflict Resolution Rule or net time domain servername set 4 These commands do not guarantee the times will remain synchronized Informix recommends that you use a product that supplies a network time protocol to ensure that times remain synchronized Stored Procedure Conflict Resolution Rule This rule allows you complete flexibility to determine which row prevails in the database You can assign an SPL procedure as the primary conflict resolution rule If you use an SPL procedure as a secondary conflict resolution rule the time stamp conflict resolution rule must be the primary rule Enterprise Replication passes the following information to an SPL procedure as arguments Enterprise Replication Processes 7 17 Time Stamp Conflict Resolution Rule ee rT Argument Description Server name CHAR 18 From the local target row null if local target row does not exist Time stamp DATETIME YEAR TO SECOND From the local target row null if local target row does not exist Local delete table i
198. in a replicate Informix database servers manage the logical log in a circular fashion where the most recent logical log entries write over the oldest entries If the database server comes close to overwriting a logical log that Enterprise Replication has not yet processed user transactions are blocked until Enterprise Replication can advance This situation where user transactions are blocked happens only if the system is severely misconfigured Reading the logical log must advance far enough to prevent new logical log entries from overwriting the logs Enterprise Replication has not yet processed The row images that participate in replicates are passed to Enterprise Replication for further evaluation Enterprise Replication Processes 7 3 Evaluating Data for Replication Evaluating Data for Replication Enterprise Replication evaluates transactions based on a distinct time and a change to a final image of a row Evaluating Time Most Enterprise Replication commands are issued at a distinct time A command does not completely take effect until Enterprise Replication processing passes the time in the logical log at which the command was issued Figure 7 1 illustrates how Enterprise Replication determines the correct data to capture and replicate based on a distinct time Figure 7 1 Evaluating a Logical log Distinct Time Evaluating distinct i AAA times 4 Transaction A 10 45 A
199. in the database server log file After issuing the cdr stop command replication threads remain stopped even if the database server is stopped and restarted until a cdr start command is issued Warning If you issue cdr stop and database activity continues the database server from which the command is issued and the other database servers participating in replicates will become inconsistent To ensure consistency verify that no database update activity occurs while Enterprise Replication is stopped 11 68 Guide to Informix Enterprise Replication cdr stop Example The following example stops Enterprise Replication processing on database server paris Processing does not resume until a cdr start command restarts 1t cdr stop c paris Command Line Utility 11 69 cdr stop group cdr stop group cdr stop group The cdr stop group command stops capture and transmittal transactions for replicates contained in a replicate group Syntax repl_ group Connect Option server_ group p 11 8 Element Purpose Restrictions repl_group Name of replicate group to stop The group must be a currently Identifiers p 8 8 active group server_group Name of server group on which The server group s must be Database Server to stop the replicate group defined for Enterprise Group p 11 12 Replication Usage The cdr stop group command causes all replicates in the replicate group repl_group to enter the inactive s
200. ing this type of resolution do not use any special Enterprise Repli cation columns This value is mutually exclusive with R_TIMESTAMP and R_STOREDPROC Resolution type R_TIMESTAMP The replication time stamp determines which update will prevail This value is mutually exclusive with R_IGNORE and R_TIMESTAMP Resolution type R_STOREDPROC A stored procedure that the structure member attrs primary storedproc specifies is used to resolve the conflict If you set this flag you must allocate a CDR_conf structure and set the primary field This value is mutually exclusive with R_IGNORE and R_TIMESTAMP If you set R_STOREDPROC you can set the stored procedure behavior to R STOREDPROC_OPTM or R_STOREDPROC_EXEC Stored procedure R_STOREDPROC_OPTM Optimize behavior the replicated row is accepted and behavior the stored procedure is not called even when conflict is detected if the replicated row is from the same database server that last updated the local row on the target table and the replicated row has a time stamp greater than or equal to the local row This value is mutually exclusive with R_STOREDPROC_EXEC Stored procedure R_STOREDPROC_EXEC Execute behavior the stored procedure defined for the behavior replicate is always called when conflict is detected This value is mutually exclusive with R_STOREDPROC_OPTM q _ _ ER API Functions 12 17 cdr_define_serv cdr_define_serv The cdr_define_ser
201. ion Icon Description Identifies information that relates to the Informix Global GLS Language Support GLS feature Identifies information that is specific to UNIX platforms WIN NT Identifies information that is specific to the Windows NT environment Introduction 9 Command Line Conventions These icons can apply to an entire section or to one or more paragraphs within a section If an icon appears next to a section heading the information that applies to the indicated feature product or platform ends at the next heading at the same or higher level A symbol indicates the end of feature product or platform specific information that appears within one or more paragraphs within a section Command Line Conventions This section defines and illustrates the format of commands that are available in Informix products These commands have their own conventions which might include alternative forms of a command required and optional parts of the command and so forth Each diagram displays the sequences of required and optional elements that are valid in a command A diagram begins at the upper left corner with a command It ends at the upper right corner with a vertical line Between these points you can trace any path that does not stop or back up Each path describes a valid form of the command You must supply a value for words that are in italics You might encounter one or more of the following elements on a co
202. ion enabled for the replicate group the replicates defined to the replicate group retain the time based frequency that was set for the replicate group To delete a replicate group using the CLU refer to cdr delete group on page 11 38 Adding Replicate s to an Existing Replicate Group To add replicates to an existing replicate group select the replicate group and then choose Group Add Replicates The Replicates list in the Add Repli cates dialog box shows all replicates that are not already included in the replicate group Select the replicate s to add to the replicate group and click Add To add replicates to a group using the CLU refer to cdr change group on page 11 20 Removing Replicate s from an Existing Replicate Group To remove a replicate from an existing replicate group select the replicate and choose Group Remove Replicate To remove replicates from a group using the CLU refer to cdr change group on page 11 20 Enterprise Replication Menus 8 21 Changing the State of a Group Changing the State of a Group The second group of choices on the Group menu allow you to change the state of a group A group can be in one of the following states m Active m Inactive m Quiescent m Suspended Active A replicate group assumes an active state if all replicates in the replicate group are active To change the state of a replicate group from inactive to active choose Group gt Start Group When y
203. ion of Return Codes Numeric Mnemonic Value Description struct CDR_EOWNER 19 Table does not exist CDR_plist No namespace in database for owner specified CDR_EPACTIVE 20 Server already participating in replicate CDR_plist 21 not in use CDR_EPKEYSELCT 22 Primary key not contained in select clause 23 not in use 24 not in use CDR_EREPACTIVE 25 Replicate already participating in a group CDR_idlist CDR_EREPDEF 26 Group operation not permitted on replicate CDR_idlist 27 not in use CDR_EREPLUNIQ 28 Replicate name already in use CDR_ETBLDNE 29 Table does not exist CDR_plist CDR_EREPSTATE 30 Illegal replicate state change CDR_idlist CDR_EREPUNDEF 31 Undefined replicate CDR_idlist CDR_ESENDQ 32 dbspace specified for the send queue does not exist CDR_ESERVDEF 33 Server not participant in replicate group CDR_idlist 34 not in use CDR_ESERVRESOLV 35 Server not defined in sqlhosts CDR_ESERVSET 36 Disjoint servers for replicates CDR_idlist CDR_ESERVUNDEF 37 Undefined server CDR_plist CDR_ESPDNE 38 Stored procedure does not exist CDR_conf Undefined stored procedure 2 of 6 Return Codes C 3 Definition of Return Codes Numeric Mnemonic Value Description struct CDR_ESQLSYN 39 Illegal select syntax CDR_plist The SELECT statement uses illegal syntax CDR_ESQLUNSUP 40 Unsupported SQL syntax join and so on 41 not in use CDR_ETIME 42 Invalid time CDR_EVALID 43 Participants required for specified operation The R_PARTICIPAN
204. ipants in a replicate Syntax include cdrapi h int cdr_modify_replmode repl participants which char repl CDR_plist participants void which repl is the replicate name participants is the list of participants which points to information if an error occurs See Using the Stored Error Information on page C 1 Usage The cdr_modify_replmode function modifies the modes of replicate partic ipant participants in replicate repl The partmode field of each participant structure sets the mode of the participant For the definition of the CDR_plist structure refer to API Structures on page 12 5 For a description of the attributes in the CDR_plist structure refer to cdr_define_repl on page 12 14 If the value of partmode is A RDONLYMODE then the participant is in read only state where updates made to the replicated table on the database server for this participant are not replicated If the value of partmode is A_PRIMARYMODE then the participant is in primary state where updates made to the replicated table on the participant database server are replicated A_PRIMARYMODE is the default mode API Functions 12 27 car_modify_serv cdr_modify_serv The cdr_modify_serv function modifies the Enterprise Replication attributes of a database server Syntax include cdrapi h int cdr_modify_serv server attrs char server CDR_serv_attrs attrs server is the name of a database se
205. ipcshm myhost XYZ g g_aserver 11 12 Guide to Informix Enterprise Replication Return Codes All the database server names dbservername and dbserver aliases must be grouped together after the line that defines the database server group Tip Ifyou are using UNIX exclusively you can assign the same name to the data base server group and the database server to avoid having to remember when to use the name of the database server group or the name of the database server You cannot do this ifyou use ERM or ifany of your database servers reside on Windows NT com puters Server Groups on Windows NT With Dynamic Server Version 7 31 use the IECC Add Database Servers wizard to prepare the SOLHOSTS connectivity information With Dynamic Server Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction for information about preparing the SOLHOSTS connectivity information Return Codes If the command has an error the database server returns an error message and a return code value The message briefly describes the error The return code value corresponds to the return code values listed in Appendix C For example the following command is incomplete because it does not include a conflict resolution rule The 58 is the error number as listed in Appendix C gt cdr def rep r12 hostl g_svrl informix customer select from customer
206. it on a single line so it is continued on the next line The second example which uses short forms for the options fits on one line cdr define server connect ohio idle 500 send dbsl A recv dbs2 ats cdr ats cdr define server c ohio 1 500 s dbs1 r dbs2 A cdr ats Check the documentation of your operating system to find out how to manage long lines at your command prompt Connect Option The connect option causes the command to use the global catalog that is on the specified server If this option is not invoked the connection defaults to the database server that the INFORMIXSERVER environment variable specifies c server connect server c server_group connect server_ group Element Purpose Restrictions server Name of the database server to Must be the name of a database Identifiers p 8 8 connect to server that is registered with Enterprise Replication server_group Name of the server group that Must be the name of anexisting Identifiers p 8 8 includes the database server to database server group connect to 11 8 Guide to Informix Enterprise Replication Participant You must use the connect option when you add a database server to your replication environment with the cdr define server command You might use the connect option if the database server to which you would normally attach is unavailable or in some limited cases to improve efficiency For more information about the global cata
207. lSalary end if end procedure D 4 Guide to Informix Enterprise Replication Column Mapping Column Mapping You can reorder columns between replicated tables Each participant in the replication system must define the identical number of columns n to n mappings only These columns must define the same domains No data conversions are performed by column mapping Column mapping is defined by the enumerations of columns in the select statement that accompanies each participant in a replication system For example in Figure D 2 Table X with columns XC1 XC2 and XC3 maps to columns BC1 BC2 and BC3 in Table B Figure D 2 Column Mapping data data The columns map as follows XC1 to BC3 XC2 to BC2 and XC3 to BC1 The SELECT statements would then read SELECT XC1 XC2 XC3 FROM Table X SELECT BC3 BC2 BC1 FROM Table B Fine Tuning Enterprise Replication D 5 Step by Step Procedure Step by Step Procedure Replication is defined and controlled with a few simple steps The following example shows three sites in the replication system m Bangor Maine m Ames lowa m Milpitas California Each site has a database named general Each site has equivalent sqlhosts files UNIX or SOLHOSTS registry key entries Windows NT that identify each of the database servers and server groups The table employees is to be replicated among all three sites The database general has the following sc
208. le Enhance GLS to replicate multiple locales within a single replication environment command line utility Scripting view in the replication manager GUI Documentation Conventions This section describes the conventions that this manual uses These conventions make it easier to gather information from this and other volumes in the documentation set The following conventions are discussed Typographical conventions Icon conventions Command line conventions Sample code conventions Screen illustration conventions Introduction 7 Typographical Conventions Convention KEYWORD Typographical Conventions This manual uses the following conventions to introduce new terms illustrate screen displays describe command syntax and so forth Meaning All primary elements in a programming language statement keywords appear in uppercase letters in a serif font italics italics italics Within text new terms and emphasized words appear in italics Within syntax and code examples variable values that you are to specify appear in italics boldface boldface Names of program entities such as classes events and tables environment variables file and pathnames and interface elements such as icons menu items and buttons appear in boldface monospace monospace Information that the product displays and information that you enter appear ina monospace typeface KEYSTROKE Keys that you are to pre
209. le specifies the names of replicates cdr list repl rOne rTwo The following output might result from the previous command REPLICATE SERVER STATE TABLE SELECT rOne g_srvl INACT customer Select from informix state r ne g_srv2 INACT customer Select from informix state rTwo g_srvl INACT customer Select addressl address2 city company customer_num fname lname phone state zipcode from informix customer rTwo g_srv2 INACT customer Select addressl address2 city company customer_num fname lname phone state zipcode from informix customer Command Line Utility 11 49 cdr list server cdr list server The cdr list server command displays a list of the Enterprise Replication servers that are visible to the current server Syntax cdr list server p 11 8 q Connect Option J server_ group Usage The cdr list server command displays information about servers You do not need to be user informix to use this command In ERM this information is displayed from Server Server Properties Listing All Enterprise Replication Servers When no server group name is given the cdr list server command lists all database server groups that are visible to the current replication server For example cdr list server might give the following output SERVER ID STATE STATUS CONNECTION CHANGED g_svrl 33 Active Connected Mar 19 17 31 51 1999 g_svr2 34 Active Dropped Mar 19 18 04 28 1999 g_svr3 22 Active The SERVER
210. led usage message enter cdr variation h For example cdr list server h The following table shows a few examples of the cdr commands Command Options Target Other Objects cdr define group connect ohio accounts replicatel replicate2 cdr modify group sequential accounts cdr sta gro c ohio accounts g_serverl g_server2 cdr def ser I L S corporate storel cdr list replicate replicatel Important You must be user informix to execute any of the CLU commands except the cdr list options 11 4 Guide to Informix Enterprise Replication List of Commands List of Commands The following table shows the commands and the page where the command is documented Command Page cdr change group 11 20 cdr change replicate 11 22 cdr connect server 11 24 cdr define group 11 25 cdr define replicate 11 27 cdr define server 11 33 cdr delete group 11 38 cdr delete replicate 11 39 cdr delete server 11 40 cdr disconnect server 11 43 cdr error 11 44 cdr list group 11 47 cdr list replicate 11 48 cdr list server 11 50 cdr modify group 11 53 cdr modify replicate 11 55 cdr modify server 11 59 cdr resume group 11 61 cdr resume replicate 11 62 cdr resume server 11 63 cdr start 11 64 1 of 2 Command Line Utility 11 5 Command Line Abbreviations Command Page cdr start group 11 66 cdr start replicate 11 67 cdr stop 11 68 cdr stop
211. licate These menu items produce the same results as the replicate and database server icon Toolbar and Status Bar You can also choose to view or hide the toolbar and the status bar The Toolbar and Status Bar menu items cause the Toolbar and Status Bar to appear or disappear from the display 8 32 Guide to Informix Enterprise Replication Window Menu Window Menu The Window menu lets you arrange the windows on your display change Replication Manager modes and activate different windows Use the Window menu to arrange your windows on your workstation The following options appear on the Window menu Option Function New List Window Creates a new window This option is helpful if you want to view different information simultaneously For example you can show database server states in one window and replicate states in another window Cascade Cascades the windows That is it overlaps windows on top of each other in a hierarchical order Tile Tiles the windows That is it places the windows next to Arrange Icons Expert Mode Database server name number Nonexpert Mode each other with no overlap Arranges the icons for the minimized windows at the bottom of the main window Toggles between expert and nonexpert mode If the choice has a check mark beside it you are in expert mode Activates the selected window Each time you create a new window ERM adds a numbered entry to the list of windows To s
212. licates In the main window you can click the replicate icon ES to see replicates and participants as Figure 8 4 illustrates A Figure 8 4 e Replication Manager g japan Replicate View Slimm HN 9 italy Active fiw g_usa primary Active To use the Replicate menu select a replicate and then choose an item from the menu The Replicate menu has the following options Define Replicate Delete Replicate Add Participant s Remove Participant s Start Replicate Participant Stop Replicate Participant Suspend Replicate Resume Replicate Change to Primary Change to Target expert mode only Replicate Properties Participant Properties 8 12 Guide to Informix Enterprise Replication Managing Replicates and Participants Managing Replicates and Participants The first four items on the Replicate menu allow you to define and delete replicates and to add and remove participants Defining a Replicate To define a new replicate choose Replicate gt Define Replicate The Define Replicate wizard appears and guides you through the steps for defining a replicate Defining a Replicate on page 9 4 describes the Define Replicate wizard To define a replicate with the CLU refer to cdr define replicate on page 11 27 Deleting a Replicate To delete a replicate select the replicate and then choose Replicate gt Delete Replicate ERM asks you to verify that the pa
213. lish format conventions for dates times and currency and also supports the ISO 8859 1 or Microsoft 1252 code set which includes the ASCII code set plus many 8 bit characters such as and If you plan to use nondefault characters in your data or your SQL identifiers or if you want to conform to the nondefault collation rules of character data you need to specify the appropriate nondefault locale For instructions on how to specify a nondefault locale additional syntax and other considerations related to GLS locales see the Informix Guide to GLS Functionality Demonstration Databases The DB Access utility which is provided with your Informix database server products includes one or more of the following demonstration databases m The stores_demo database illustrates a relational schema with infor mation about a fictitious wholesale sporting goods distributor Many examples in Informix manuals are based on the stores_demo database m The superstores_demo database illustrates an object relational schema The superstores_demo database contains examples of extended data types type and table inheritance and user defined routines For information about how to create and populate the demonstration databases see the DB Access User s Manual For descriptions of the databases and their contents see the Informix Guide to SQL Reference The scripts that you use to install the demonstration databases reside in the INFORMI
214. lized for final processing Update Anywhere Replication In update anywhere replication changes made on any participating database server are replicated to all other participating database servers When you use update anywhere replication users at two or more different database servers might update the same row at the same time To cope with this situation you must provide rules for conflict resolution Conflict Resolution When multiple database servers try to update the same row at the same time Enterprise Replication must determine which new data to replicate To solve conflict resolution you must specify a conflict resolution rule and the conflict resolution scope Enterprise Replication Features 2 15 Conflict Resolution Rules For a detailed discussion of conflict resolution refer to Evaluating Data for Replication on page 7 4 Conflict Resolution Rules A conflict occurs when two database servers attempt to modify the same piece of data Enterprise Replication has the following four conflict resolution rules m Ignore The ignore rule does not attempt to detect conflicts m Time stamp The row or transaction with the most recent time stamp is applied m Stored procedure An SPL procedure that you provide determines which data should be applied Procedures for conflict resolution must be in SPL Enterprise Repli cation does not allow user defined routines in C or in Java m Time stamp with stored procedur
215. llowing exceptions m You cannot change the canonical float format m You cannot change the conflict resolution from ignore to a non ignore option or from non ignore to ignore However you can change from time stamp resolution to procedure resolution or from procedure resolution to time stamp m The ATS RIS and Fire Triggers options require a yes y or no n argument 11 56 Guide to Informix Enterprise Replication cdr modify replicate Special Options Special Options Back to cdr modify replicate p 11 55 The special options for cdr define replicate have the meanings shown in the following table Options Long Form Short Form Meaning ats A Activate y or deactivate n aborted transaction spooling for replicate transactions that fail to be applied to the target database For more information see Chapter 10 firetrigger T Cause the rows inserted by this replicate to fire y or not fire n triggers at the destination ris R Activate y or deactivate n row information spooling for replicate row data that fails conflict resolution or encounters replication order problems For more information see Chapter 10 Command Line Utility 11 57 car modify replicate Examples The following example modifies the frequency attributes of replicate smile to replicate every 5 hours cdr modify repl every 300 smile The following example modifies the frequency attributes of replicate smil
216. llows Informix products to handle different languages cultural conventions and code sets Enterprise Replication provides limited support for user defined data types Operating Modes The Enterprise Replication Manager ERM provides two operating modes nonexpert and expert The nonexpert operating mode supports only primary target replication and requires that all participating database servers be fully interconnected The expert operating mode supports all ownership models and hierarchical replication Easy Centralized Administration Administrators must be able to easily manage all the distributed components of the replication system from a single point of control ERM a Windows NT GUL allows an administrator to define and manage the replication system You do not need to shut down the entire replication system to add database servers to the replication system For information about ERM see Chapter 8 Enterprise Replication Menus You can also use the command line utility CLU to administer the replication system from your system command prompt This utility is documented in Chapter 11 Command Line Utility An Enterprise Replication global catalog a system database table on each database server keeps track of Enterprise Replication configuration infor mation The global catalog maintains information such as replication definitions Enterprise Replication servers conflict detection and resolution rules and their
217. load utility on HPL Copy the unloaded data to delta Start transactions with BEGIN WORK WITHOUT REPLICATION load the data using the LOAD statement and commit the transaction If you used the HPL to unload the data in step 5 then use the HPL Deluxe load without replication to load the data into table1 on delta Resume server delta on alpha beta and gamma This step starts the flow of data from alpha beta and gamma to delta At this point you might see some transactions aborted because of conflict Transaction can abort because alpha beta and gamma started queueing data from delta in step 4 However those same transactions might have been moved in steps 5 and 7 It might seem strange to declare replication on server delta and then immedi ately suspend replication You must do this because while you are preparing the replicates and unloading and loading files the other servers in the replicate alpha beta and gamma might be collecting information that needs to be replicated After you finish loading the initial data to delta and resume replication the information that was generated during the loading process can be replicated Beginning Work Without Replication You might need to put data into a database that you do not want replicated perhaps for a new server or because you had to drop and re create the table Preparing Data for Replication 6 9 Beginning Work Without Replication Using DB Access to Begin Work
218. log refer to Catalog on page 2 14 Participant The participant identifies a table that should be replicated You must include the server group database table owner and table name The participant must be enclosed in quote marks This definition of a participant is used in the following CLU options m cdr define replicate m cdr modify replicate m cdr change replicate database server_ group owner table Element Purpose Restrictions Syntax database Name of the database that The database server must be Identifiers p 8 8 includes the table to be replicated registered with Enterprise Replication User ID of the owner of the table None Identifiers p 8 8 to be replicated server_group Name of the server group that Must be the name of an existing Identifiers p 8 8 includes the server to connect to server group table Name of the table to be replicated The table must be an actual table Identifiers p 8 8 It cannot be a synonym or a view Command Line Utility 11 9 Participant UNIX WIN NT Using the O and I Options The O owner option causes permission checks for owner to be applied to the operation such as insert or update that is to be replicated and to all actions fired by any triggers When the O option is omitted all operations are performed with the privileges of user informix If a trigger requires any system level commands as specified using the system command in
219. makes the replication system more efficient because the global catalogs do not need to be replicated to the leaf servers Replication Types Enterprise Replication provides two types of data replication m Primary target m Update anywhere For a discussion of ways in which these replication types are used refer to Chapter 4 Selecting Enterprise Replication Systems For examples of simple replications refer to Chapter 3 Replication Examples 2 14 Guide to Informix Enterprise Replication Primary Target Replication Primary Target Replication In primary target replication all database changes originate at the primary database and are replicated to the target databases Changes at the target databases are not replicated to the primary A primary target replication system can provide one to many or many to one replication One to Many Replication In the one to many or distribution replication all changes to a primary database server are replicated to many target database servers You might use this replication model when information gathered at a central site must be disseminated to many scattered sites Many to One Replication In many to one replication or consolidation replication many primary servers send information to a single target server You might use this repli cation model when many sites are gathering information for example local field studies for an environmental study that needs to be centra
220. mary Adding a Participant Defining a Replicate Group Choosing a Group Name Choosing the Replication Interval fe ihe Grup Selecting Replicates for the Replicate Group Generic Configuration Wizard Choosing a Naming Scheme Describing the Replicates Describing the Participants Customizing the Generic Replicates 8 33 8 33 8 34 8 34 8 35 8 35 8 37 8 37 8 37 8 38 8 39 9 3 9 4 9 4 9 5 9 6 9 9 9 10 9 12 9 13 9 14 9 15 9 15 9 16 9 16 9 17 9 17 9 18 9 20 9 21 9 23 Table of Contents ix Chapter 10 Diagnosing Enterprise Replication In This Chapter Aborted Transaction Schelling Preparing to Use ATS BYTE and TEXT Information in ATS Files Row Information Spooling BYTE and TEXT Informatoni in RIS Files Replication Event Monitor Messages Chapter 11 Command Line Utility In This Chapter List of Commands Command Line Abbreviations Option Abbreviations Order of the Options Backslash Use Connect Option Participant Participant Modifier Database Server Groups Return Codes Frequency Options Example Using the Command Line se Utility Command Line Utility Syntax cdr change group cdr change replicate cdr connect server cdr define group cdr define replicate cdr define server cdr delete group cdr delete replicate cdr delete server cdr disconnect server cdr error cdr list group cdr list replicate cdr list server cdr modif
221. me column definitions The information in the tables represents only trans actions in memory and not those spooled to disk The ctstamp1 and ctstamp2 columns combine to form the primary key for these tables Column Type Description ctkeyserverid integer Server ID of the database server where this data originated This server ID is group ID from the sqlhosts file or the SOLHOSTS registry key ctkeyid integer Logical log ID ctkeypos integer Position in the logical log on the source server for the transaction represented by the buffer 1 of 2 SMI Tables for Enterprise Replication B 3 Columns of the Buffer Tables Column ctkeysequence ctstamp1 ctstamp2 ctcommittime ctuserid ctfromid Column cbflags cbsize cbkeyserverid cbkeyid cbkeypos B 4 Guide to Informix Enterprise Replication Type integer integer integer integer integer integer Type integer integer integer integer integer Description Sequence number for the buffer within the transaction Together with ctstamp2 forms an insertion stamp that specifies the order of the transaction in the queue Together with ctstamp1 forms an insertion stamp that specifies the order of the transaction in the queue Time when the transaction represented by this buffer was committed Login ID of the user who committed this transaction Server ID of the server that sent this transaction Used only in hierarchical repl
222. me stamp resolution rule behaves differently depending on which scope you choose for conflict resolution row by row or transaction as follows m Row by row conflict resolution scope Enterprise Replication evaluates one row at a time The row with the most recent time stamp wins the collision and is applied to the target database servers If an SPL procedure is defined as a secondary conflict resolution rule the procedure resolves the conflict when the row times are equal m Transaction conflict resolution scope Enterprise Replication evaluates the most recent row update time among all the rows in the replicated transaction This time is compared to the time stamp of the appropriate target row If the time stamp of the replicated row is more recent than the target the entire replicated transaction is applied If a procedure is defined as a secondary conflict resolution rule itis used to resolve the conflict when the time stamps are equal Tip A secondary procedure is invoked only if Enterprise Replication evaluates rows and discovers equal time stamps If either conflict resolution scope row by row or transaction evaluates rows and discovers equal time stamps and no procedure is defined as a secondary conflict resolution rule the replicated row or transaction is applied Figure 7 11 on page 7 16 shows how a conflict is resolved based on the latest time stamp with row by row scope The time stamp Tlast_update represents the ro
223. mited SQL Statements Permitted SQL Statements Capacity Planning Logical Log Records Ky Send and Receive Message Queues Delete Tables Spooling Directories Configuration Parameters Enterprise Replication Threads Environmental Considerations Time Synchronization Transaction Processing Effect Using Unbuffered Logging Analyzing Replication Volume Using Complex SELECT Statements Enterprise Replication Data Types Replicating on Heterogeneous Hardware Replicating Simple Large Objects Replicating from Tablespaces or Blobapaces Conflict Resolution for Simple Large Objects Evaluating BYTE and TEXT Data with SPL Procedures 5 3 5 3 5 3 5 4 5 4 5 4 5 5 5 6 5 7 5 7 5 8 5 8 5 9 5 10 5 10 5 10 5 10 5 11 5 11 5 11 5 11 5 12 5 13 Replicating User Defined Data Types 5 15 Replicating Smart Large Objects 2 2 we 9 15 Using GLS with Enterprise Replication 5 15 5 2 Guide to Informix Enterprise Replication In This Chapter Before you install Enterprise Replication you need to determine what changes to make to your open systems environment This chapter discusses the various operational limitations capacity requirements and system changes you need to make based on the Enterprise Replication system you select The chapter also discusses the data types that you can use for replication Operational Limitations Enterprise Replic
224. mix Welcomes Your Comments 2 Guide to Informix Enterprise Replication 16 16 In This Introduction This Introduction provides an overview of the information in this manual and describes the conventions it uses About This Manual This manual contains information to help you understand the concepts of data replication install Enterprise Replication design your replication system and administer and manage data replication throughout your enterprise Informix Enterprise Replication provides you with an efficient way to replicate data asynchronously throughout your open systems enterprise Enterprise Replication is a client server application that operates on UNIX and Windows NT The Enterprise Replication Manager ERM a Windows NT based graphical user interface GUI helps you easily define monitor and control your replication system Introduction 3 Types of Users WIN NT Types of Users This manual is for database server administrators This manual assumes that you have the following background m A working knowledge of your computer your operating system and the utilities that your operating system provides m Some experience working with relational databases or exposure to database concepts m Some experience with database server administration operating system administration or network administration If you have limited experience with relational databases SOL or your operating system refer to you
225. mmand line path Element Description command This required element is usually the product name or other short word that invokes the product or calls the compiler or preprocessor script for a compiled Informix product It might appear alone or precede one or more options You must spell a command exactly as shown and use lowercase letters variable A word in italics represents a value that you must supply such as a database file or program name A table following the diagram explains the value flag A flag is usually an abbreviation for a function menu or option name or for a compiler or preprocessor argument You must enter a flag exactly as shown including the preceding hyphen 1 of 2 10 Guide to Informix Enterprise Replication Command Line Conventions Element Description ext A filename extension such as sql or cob might follow a variable that represents a filename Type this extension exactly as shown immediately after the name of the file The extension might be optional in certain products Punctuation and mathematical notations are literal symbols that you must enter exactly as shown Single quotes are literal symbols that you must enter as shown Privileges p 5 17 A reference in a box represents a subdiagram Imagine that the subdiagram is spliced into the main diagram at this point When a page number is not specified the subdiagram appears on the same page
226. mmary The Replicate Summary page in Figure 3 17 lets you review the attributes of the replicate before ERM actually creates the replicate Read the summary to verify that it shows the choices that you made If you are not satisfied click Cancel to revise your replicate If the summary is correct click Create Figure 3 17 Replicate Summary may of repl3 3 32 Guide to Informix Enterprise Replication Viewing the Replicate Viewing the Replicate When you click Create on the Replicate Summary page as Figure 3 17 on page 3 32 shows ERM creates the replicate and returns to the main ERM display Click the replicate icon E in the upper left part of the display ERM lists the replicates that you definea If you reinitialized your database servers in Removing Previously Defined Replication Servers on page 3 17 the list has only one replicate rep13 Click the plus beside rep13 to list the database servers that are participants in the replicate Figure 3 18 shows the participants in repl3 Figure 3 18 Display of repI3 ot Replication Manager g japan llo jaran E g_italy Inactive g_usa primary Inactive Replication Examples 3 33 Activating the Replicate Activating the Replicate Figure 3 18 shows that both g_italy and g_usa are inactive in rep13 Although you have defined the replicate no changes will be replicated until you make the replicate active To activate the replicate select rep13 and then
227. modify defined in Enterprise Group p 11 12 Replication Command Line Utility 11 59 car modify server Usage The cdr modify server command modifies the replication server server_group The options for cdr modify server have the meanings that the following table shows Options Long Form Short Form Meaning ats A Activate aborted transaction spooling for replicate transactions that fail to be applied to the target database For more information see Chapter 10 idle i Causes an inactive connection to be terminated after idle time mode m Change the mode of all replicates using this server to primary or to read only You can use the abbrevia tions p and r for primary and read only respectively ris R Activates row information spooling for replicate row data that fails conflict resolution or encounters replication order problems For more information see Chapter 10 Examples The following example connects to the database server paris and modifies the idle time out of server group g_rome to 10 minutes ATS files go into the directory cdr atsdir cdr modify server c paris i 10 A cdr atsdir g_rome The following example connects to the default database server and sets the modes of all participants on g_geometrix to primary cdr modify server m primary g_geometrix 11 60 Guide to Informix Enterprise Replication cdr resume group cdr resume group The cdr resume group command resumes deliv
228. n Servers Using Previously Defined Replication Servers Defining the First Replication Server The Declare Server Dialog Box for Nowiicpert Mode The Declare Server Dialog Box for dd Mode Choosing Nonexpert Mode Displaying the List of Servers Defining a Replication Server on italy Creating the Primary Target Replicate 3 3 3 3 3 5 3 6 3 6 3 8 3 9 3 9 3 9 3 12 3 12 3 13 3 13 3 14 3 14 3 16 3 17 3 17 3 18 3 18 3 20 3 22 3 23 3 23 3 24 3 26 Choosing a Name for the Replicate Specifying the Replication jah aes A Selecting the Participants Selecting the Primary Selecting a Table Selecting the Columns Summary Viewing the Replicate Activating the Replicate Cause a Replication Do Not Cause a Replication Update Anywhere Example Using ERM Changing to Expert Mode Creating an Update Anywhere Renicate Choosing a Replicate Name and Type Specifying a Conflict Rule i Specifying the Replication Options Specifying the Frequency Selecting the Participants Participants Identical Selecting a Table Selecting the Columns Summary Viewing the Replicate a Defining a Replication Server on japan Adding a Participant to repl4 Selecting a New Participant Specifying a Table and Columns Activating the Replicate Cause a Replication Hierarchy Example Using ERM ty ee Deleting the Previously Defined Servers Defining the Nonroot Replication Servers Definin
229. n dbspace1 and the receive queues should be stored in dbspace2 Any files that ATS generates will go connect stan idle 500 send dbspacel ats cdr ats init g_stan cdr define server The following example connects to the database server oliver initializes Enterprise Replication synchronizes its catalogs with the catalogs on database server stan and defines the database server oliver with an idle time out of 600 minutes The send queue will be created in dbspaceA and the receive queues will be created in dbspaceB Also any files that ATS generates will go into directory cdr ats cdr define server c oliver i 600 s dbspaceA r dbspaceB A cdr ats I S stan oliver Command Line Utility 11 37 car delete group cdr delete group The cdr delete group command deletes a replicate group Syntax cdr delete group repl_ group p 11 8 Element Purpose Restrictions Syntax repl_group Name of replicate group to delete The group must exist Identifiers p 8 8 Usage The cdr delete group command deletes the replicate group repl_group from the global catalog The cdr delete group command does not affect the replicates or associated data When a replicate group is deleted the individual replicates within the group are unchanged Example The following example connects to the default database server and deletes the replicate group accounts cdr delete group accounts 11 38 Guide to Informi
230. n updates the row two seconds before Bangkok updates the same row The Bangkok update arrives at the India site first and the Pakistan update follows The Pakistan time T is earlier than the Bangkok time Because both updates involve the same data and a time discrepancy exists Enterprise Replication detects a collision Choosing Conflict Resolution Rules and Scopes You need to determine conflict resolution rules and a conflict resolution scope for each replicate Tip ERM supports two operating modes expert and nonexpert Expert mode provides more options for control of your Enterprise Replication system than standard mode The CLU see Chapter 11 and the APIs see Chapter 12 do not distinguish between these two modes The CLU and APIs provide all expert mode options Enterprise Replication supports up to two conflict resolution rules for each replicate You can define a primary rule and a secondary rule if desired Figure 7 10 shows the valid combinations of Enterprise Replication conflict resolution rules Enterprise Replication Processes 7 13 Choosing Conflict Resolution Rules and Scopes Figure 7 10 Valid Conflict Resolution Rule Combinations Enterprise Replication Primary Rule Secondary Rule Operating Mode Support Time stamp None Expert Time stamp Stored procedure Expert Stored procedure None Expert Ignore None Standard and expert Each conflict resolution rule behaves differently
231. name that specifies the send queue bytes can be no longer than 256 characters Each message contains the filtered log records for a single transaction Target sites acknowledge receipt of a message when the message is safely stored A message is safely stored when it is in a stable recoverable queue or when it is in the target database If a target database server is unreachable the replication messages remain in a stable queue at the source database server Temporary failures are common and no immediate action is taken by the source database server it continues to queue transactions When the target database server becomes available again queued transactions are transmitted and applied see Applying Data for Distribution on page 7 12 Enterprise Replication Processes 7 11 Applying Data for Distribution If the target database server is unavailable for an extended period the send queue on the source database server might consume excessive resources It might not be appropriate to save all transactions for the remote database server in this situation To prevent unlimited transaction accumulation the unavailable target database server can be removed from the replicate The database server thatis removed needs to synchronize with the other database servers before it rejoins any replicate For more information see Chapter 6 Preparing Data for Replication Applying Data for Distribution Enterprise Replication applies th
232. ndicator CHAR 1 m Y indicates the origin of the row is the delete table or m K indicates the origin of the row is the replicate key Local key delete row indicator CHAR 1 delete row for a key update that is sent as a key delete and a key insert because the local target row with the old key does not exist Server name CHAR 18 Of the replicate source Time stamp DATETIME YEAR TO SECOND From the replicated row Replicate action type CHAR 1 I insert D delete U delete update Local row data returned in regular SOL format Where the regular SQL format is taken from the SELECT clause of the participant list Replicate row data after image returned in Where the regular SQL format is taken from the SELECT regular SQL format clause of the participant list 7 18 Guide to Informix Enterprise Replication Time Stamp Conflict Resolution Rule The procedure must set the following arguments before the procedure can be applied to the replication message Argument Description An indicator of the desired database operation Same as the replicate action codes with the following to be performed CHAR 1 additional codes m A accept the replicated row and resolve replication exception m S accept the replicated row as received m 0 discard the replicated row m X abort the transaction A non zero integer value to request logging of Logging value takes effect only if logging is configured the resolution and
233. ng GLS with Enterprise Replication 5 15 vi Guide to Informix Enterprise Replication Chapter 6 Section III Chapter 7 Preparing Data for Replication In This Chapter Preparing Consistent Data Shadow Columns Using the High Parme Dade Using the onunload and onload Utilities Using the dbexport and dbimport Utilities Using the UNLOAD and LOAD statements Blocking Replication Data Preparation Examples Adding a New Participant to an Existing Replicate Beginning Work Without Replication Replicating Data Enterprise Replication Processes In This Chapter Capturing Transactions Evaluating Data for Replication Evaluating Time Evaluating Images of a Row Evaluating Replication Examples Evaluating Primary Key Updates Receiving and Sending Data from the Mesapa Oliei Applying Data for Distribution Choosing Conflict Resolution Rules and Scopes Time Stamp Conflict Resolution Rule Using Cascading Deletes and Triggers Using Cascading Deletes Using Triggers Table of Contents vii Chapter 8 Enterprise Replication Menus In This Chapter General Information Preparing to Use the Replication Manager Opening the Replication Manager Understanding Server Terminology Using Modes Choosing Ellipses Viewing Long Identifiers The Replication Manager Main Window i Using the Global Catalog Icon Using the What s This Icon The File Menu Creating Scripts Moni
234. nonyms m Database servers m Database server groups m Replication servers A replication server is a database server that includes a database that describes the replication environment Thus every replication server is a database server but not every database server is a replication server A database server group includes one or more database servers For some purposes all database servers in a database server group are treated as the same server In Enterprise Replication a database server group includes more than one database server only if a computer has multiple network interface cards However a database server group can include multiple database server aliases If you use DBSERVERNAME and DBSERVERALIASES the DBSERVERNAME should correspond to the SQLHOSTS entry that specifies the network connection That is DBSERVERNAME should not correspond to a shared memory connection For information about database server aliases refer to your Administrator s Guide This manual shows database servers and database server groups explicitly A database server name such as myserver never has a prefix In this manual the database server group to which myserver belongs is always prefixed with g_ for example g_myserver However ERM usually asks you to enter the name of or select a server In most cases ERM uses server to mean database server group To decide what name to use use the following guidelines m To describe the contents of
235. nstant that the command executes The system monitoring interface SMI also provides information about the database server For general information about onstat and SMI refer to the Administrator s Reference The onstat z Command The onstat z command clears database server statistics including statistics that relate to Enterprise Replication The onstat g Command The onstat g commands are provided for support and debugging only You can include only one of these options with each onstat g command This appendix describes the following onstat g commands onstat g cat onstat g ddr E m m onstat g dss m onstat g dtc m onstat g grp The onstat g cat Command onstat g nif onstat g que onstat g rcv onstat g rep onstat g rqm The onstat g cat Command The g cat option of the onstat command prints a summary of information about servers replicates replicate groups and their characteristics The onstat g cat command has the following formats onstat g cat onstat g cat scope onstat g cat replname The following table describes repIname and scope Modifier Description replname The name of a replicate scope One of the following values servers Print information on servers only repls Print information on replicates only full Print expanded information for both replicate servers and replicates F 2 Guide to Informix Enterprise Replication The onstat g ddr Command
236. nt Definition CO O CO als enn socium When you describe all the participants your display will be similar to Figure 9 13 Click Finish The Generic Configuration wizard prepares the replicates as Figure 9 15 shows Figure 9 15 E legos Sainte Vier B Replication Scripting View Generic Replicates Replication System zz_items a 22_orders 22_state 0 4 Z2_stock Replication Servers KOS g_boston g_denver 9 22 Guide to Informix Enterprise Replication Customizing the Generic Replicates Customizing the Generic Replicates After you create the generic replicates you can use the Scripting View to customize the individual replicates It is usually faster to create generic replicates and then customize as needed rather than to create each replicate individually To customize a replicate select the replicate and then change its attributes in the right hand column of the Scripting View For example all the ZZ repli cates have continuous replication but you want to change the replication of the items table to occur only occasionally Select ZZ_items Then click with the right button on Continuous to get the popup change frequency menu as in Figure 9 16 Figure 9 16 Customizing a Generic Replicate Replication Scripting View Replication Systern a A Ems i HA 22_orders Conflict Resolutio Sy 2Z_state Conflict Resolutio i zz_stock A Stored Procedure au Replic
237. o additional routing is necessary to deliver replication messages Figure 2 2 shows a fully connected replication topology Each database server connects directly to every other database server in the replication environment Figure 2 2 Europe Fully Connected p Topology Germany y Enterprise Replication Features 2 5 Replication Topology Types Hierarchical Tree A hierarchical tree consists of a root database server and one or more database servers organized into a tree topology The tree contains only one root which has no parent Each database server within the tree references its parent A database server that is not a parent is a leaf Figure 2 3 illustrates a replication tree Figure 2 3 Hierarchical Tree Topology a ee N Hong Kong In Figure 2 3 the parent child relationship within the tree is as follows m Asia is the parent of China and Japan m China is the child of Asia and the parent of Beijing Shanghai and Guangzhou m Guangzhou is the child of China and the parent of Hong Kong Asia is the root database server Japan China and Guangzhou are nonroot database servers You can define Beijing Shanghai and Hong Kong as either nonroot database servers or leaf database servers depending on how you plan to use them The dashed connection from China to Shanghai indicates that Shanghai is a leaf server 2 6 Guide to Informix Enterprise Replication Replication Topology Types Forest o
238. o examples show an SQL statement and the correct changes to the statement to modify columns o Iftablenamel is a table defined for replication the statement LOAD FROM filename INSERT INTO tablenamel must be changed to LOAD FROM filename INSERT INTO tablenamel Jist of columns The list of columns must match the order and the number of fields in the load file o Iftabnamel and tabname 2 are tables defined for replication with the same schema the statement INSERT INTO tabnamel FROM tabname2 must be changed to an explicit statement where col1 col2 colN are the columns of the table INSERT INTO tabnamel VALUES cdrserver cdrtime coll col2 colN cdrserver cdrtime FROM tabname2 The shadow columns cdrserver cdrtime are not included in an list For more information about these statements refer to the Informix Guide to SQL Syntax Preparing Data for Replication 6 7 Data Preparation Examples Data Preparation Examples The following examples illustrate how to prepare data for replication Adding a New Participant to an Existing Replicate The following steps provide an example of how to add a new participant delta to an existing replicate using the LOAD UNLOAD and BEGIN WORK WITHOUT REPLICATION statements Replicate zebra replicates data from table table1 for the following database servers alpha beta and gamma The servers alpha beta and gamma belong to the server groups g_alpha _
239. ock 3 12 Guide to Informix Enterprise Replication Hierarchy Example Using the CLU Updating the stock Table on the japan Database Server Use DB Access to change a value in the stock table on japan UPDATE stores japan stock SET unit_price 190 00 WHERE stock_num 401 Verify that the change has replicated to the stock table on usa and on italy SELECT from stores usa stock WHERE stock_num 401 SELECT from stores italy stock WHERE stock_num 401 Hierarchy Example Using the CLU The example in this section adds a replication tree to the fully connected environment of the usa italy and japan replication servers The nonroot servers boston and denver are children of usa The leaf server miami is a child of boston Figure 3 1 shows the replication hierarchy Figure 3 1 italy Hierarchical Tree Example usa boston denver nonroot nonroot e EY a Miami Replication Examples 3 13 Preparing for a Hierarchy Example Preparing for a Hierarchy Example To try this example you need to prepare three additional database servers boston denver and miami To prepare the database servers use the techniques described in Environment for the Replication Examples on page 3 3 Defining a Hierarchy The following example defines a replication hierarchy that includes denver boston and miami and whose root is usa 1 cdr define server connect boston nonroot init A 2 sync g_usa
240. odify the manufact table on the usa database server and see the change reflected in the manufact table on the italy database server Use DB Access to insert a value into the manufact table on usa INSERT INTO stores usa manufact VALUES AWN Allwyn 8 Now observe the changes on usa and on italy SELECT from stores usa manufact SELECT from stores italy manufact 3 8 Guide to Informix Enterprise Replication Do Not Cause a Replication Do Not Cause a Replication In repl1 usa is the primary database server and italy is the target Changes made to the manufact table on italy do not replicate to usa Use DB Access to insert a value into the manufact table on italy INSERT INTO storesQitaly manufact VALUES ZZZ Zip 9 Now verify that the change occurred on italy but did not replicate to the manufact table on usa SELECT from stores usa manufact SELECT from stores italy manufact Update Anywhere Example Using the CLU This example creates a simple update anywhere replication In update anywhere replication changes to any table in the replicate are replicated to all other tables in the replicate In this example any change to the stock table of the stores database on any database server in the replicate will be replicated to the stock table on the other database servers Preparing for an Update Anywhere Replication 1 cdr define replicate conflict ignore repl2 A 2 stores g_usa informix stock
241. of 500 but the data has not been changed on the source server Therefore the data is not sent from the source server 10 8 Guide to Informix Enterprise Replication UNIX WIN NT Row Information Spooling Example 3 lt Keep local blob 75400 BYTE PB 877 necromsv 840338515 96 08 17 20 21 55 gt where Keep local blob indicates that the replicated data for this column was not applied on the target table but instead the local BYTE data was kept This usually happens when time stamp conflict resolution is defined and the local column has a time stamp greater than the replicated column Row Information Spooling In addition to ATS Enterprise Replication provides another spooling option called row information spooling RIS RIS logs the following types of information m Individual aborted row errors m Replication exceptions such as when a row is converted by Enter prise Replication from insert to update or from update to insert and so on m Special stored procedure return codes as defined by the application if a stored procedure is called to resolve a conflict If you do not specify an RIS directory Enterprise Replication stores the RIS files in the tmp directory If you do not specify an ATS directory Enterprise Replication stores the RIS files in the tmp directory of the drive that contains INFORMIXDIR The pathname for the RIS directory cannot be more than 256 bytes If the default directory
242. ompression takes effect when Enterprise Replication is initialized The CDR_NIFCOMPRESS network interface compression configuration parameter specifies the level of compression that the database server uses before sending data from the source database server to the target database server Network compression saves network bandwidth over slow links but uses more CPU to compress and decompress the data The values have the following meanings Value Meaning 1 The source database server never compresses the data regardless of whether or not the target site uses compression 0 The source database server compresses the data only if the target database server expects compressed data 1 The database server performs a minimum amount of compression 9 The database server performs the maximum possible compression When Enterprise Replication is defined between two database servers the CDR_NIFCOMPRESS values of the two servers are compared and changed to the higher compression values Configuration Parameters A 5 CDR_NIFCOMPRESS The compression values determine how much memory can be used to store information while compressing as follows no additional memory 128k 1k 129k 128k 2k 130k 128k 32k 160k 128k 128k 256k 128k 256k 384k 00M nro Higher levels of CDR_NIFCOMPRES cause greater compression Different sites can have different levels For example Figure A 1 shows a set of thre
243. on message queue for distribution Enterprise Replication uses two queues to send and receive messages a send queue and a receive queue The message queue refers to the send and receive queues A row might change more than once in a particular transaction For example a transaction might insert and then update a row prior to committing Enter prise Replication evaluates the net effect final state of a transaction based on the row buffers in the log Enterprise Replication then determines what should replicate based on the net effect the initial state of the row and whether the replicate definition in particular the WHERE clause applies to the initial and final state The table in Figure 7 2 on page 7 6 shows the logic that determines which rows are candidates for replication Enterprise Replication Processes 7 5 Evaluating Images of a Row Figure 7 2 Enterprise Replication Evaluation Logic Initial Image INSERT INSERT INSERT UPDATE UPDATE UPDATE UPDATE UPDATE UPDATE UPDATE Replicate Evaluates Tor F Tor F Tor F Final Image DELETE UPDATE UPDATE DELETE DELETE UPDATE UPDATE UPDATE UPDATE UPDATE Replicate Evaluates TorF TorF TorF 7 6 Guide to Informix Enterprise Replication Primary Key Send to Destination Changed yes or no yes or no yes or no yes or no yes or no yes no yes or no yes or no yes or no Database Serve
244. on Manager g List of Replication Servers Active Replication Examples 3 25 Creating the Primary Target Replicate Creating the Primary Target Replicate This section creates a replicate that causes any change to the call_type table of the stores database on the usa database server to be replicated to the call_type table on the other database servers This replicate is equivalent to the replicate in Update Anywhere Example Using the CLU on page 3 9 except that the table replicated is call_type instead of manufact Choosing a Name for the Replicate Select Define Replicate from the Replicate menu ERM displays the introductory page of the Define Replicate wizard Click Next On the next page enter a name for the replicate rep13 Click Next Specifying the Replication Frequency When a change is made to a table that is participating in a replicate Enterprise Replication can propagate the change either immediately or at fixed intervals The default behavior propagates the change immediately On the wizard page that Figure 3 12 shows leave the frequency set at Continuous Replication Click Next 3 26 Guide to Informix Enterprise Replication Creating the Primary Target Replicate Figure 3 12 Specify Replication Frequency Replication Examples 3 27 Creating the Primary Target Replicate Selecting the Participants The wizard page in Figure 3 13 on page 3 28 lets you specify the database servers for t
245. ons that occur during this period are not replicated and hence tables can become unsynchronized API Functions 12 41 cdr_stop_group cdr_stop_group The cdr_stop_group function stops the capture and transmittal of data from replicates contained in a replicate group Syntax include cdrapi h int cdr_stop_group group servers time which char group CDR_idlist servers time_t time void which group is the replicate group name servers is an optional list of database server groups for which the repli cation should be stopped time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage All replicate data defined in the replicate group group enters the inactive state no capture no send on the database servers in the servers list If the servers list is null replication stops for all replicates in the replicate group 12 42 Guide to Informix Enterprise Replication cdr_stop_repl cdr_stop_repl The cdr_stop_repl0 function stops the capture and transmittal of data for a replicate Syntax include cdrapi h int cdr_stop_repl repl servers time which char repl CDR_idlist servers time_t time void which repl is the replicate name servers is an optional list of database server groups that include the database for
246. ool and by Informix Technical Support The onstat g rcv Command The g rev option of the onstat command prints statistics about the receive manager This option is used primarily as a debugging tool and by Informix Technical Support The onstat g rcv command has the following formats onstat g rcv onstat g rcv serverid The serverid modifier causes the command to print only those output messages received from the replication server whose groupID is serverid The onstat g rep Command The g rep option of the onstat command prints events that are in the queue for the schedule manager The g rep option is used primarily as a debugging tool and by Informix Technical Support Enterprise Replication onstat g Options F 5 The onstat g rqm Command The onstat g rep command has the following formats onstat g rep onstat g rep replname The replname modifier limits the output to those events originated by the replicate named repIname The onstat g rqm Command The g rqm option of the onstat command prints statistics and or contents of the low level queues If a queue is empty no information is printed for that queue When you specify a modifier to select a specific queue the command prints all the statistics for that queue and information about the first and last in memory transactions for that queue The FULL modifier displays information about every in memory transaction for every queue The BRIEF modifier gives
247. or a Hierarchy Example Defining a Hierarchy Primary Target Example Using ERM Removing Previously Defined Replication Servers Defining the First Replication Server Defining a Replication Server on italy Creating the Primary Target Replicate Viewing the Replicate Activating the Replicate Cause a Replication Do Not Cause a Replication Update Anywhere Example Using ERM Changing to Expert Mode Creating an Update Anywhere Replicate Viewing the Replicate Defining a Replication Server on japan Adding a Participant to repl4 Activating the Replicate Cause a Replication Hierarchy Example Using ERM Deleting the Previously Defined Servers Defining the Nonroot Replication Servers Defining a Leaf Replication Server Displaying the Hierarchy Viewing the Server Properties 3 12 3 13 3 14 3 14 3 16 B17 3 18 3 24 3 26 3 33 3 34 3 36 3 36 3 37 3 37 3 37 3 44 3 45 3 46 3 48 3 49 3 49 3 49 3 49 3 50 3 50 3 51 Table of Contents v Section II Preparing for Enterprise Replication Chapter 4 Selecting Enterprise Replication Systems In This Chapter O HS oe 4 3 Primary Target Replication sn ate a e ch Be Be py 4 3 Data Dissemination ee eee 4 4 Data Consolidation 2 ee ee 4 5 Workload Partitions 0 ee en 4 6 Workflow Replication 2 2 2 ee ee 4 7 Factors in Primary Target Systems he Oe Bi Cae es 4 7 Selecting Data
248. or that argument Usage The cdr_delete_repl function deletes the replicate rep from the global catalog All replication data for the replicate is purged from the send and queues at all participating database servers If repl is contained in a replicate group the call fails You must remove the replicate from the group before you can delete it To remove a replicate from a group see cdr_participate_group on page 12 31 API Functions 12 21 cdr_delete_serv cdr_delete_serv The cdr_delete_serv function deletes a database server from the global catalog Syntax include cdrapi h int cdr_delete_serv server char server server is the name of a database server group Usage The cdr_delete_serv function deletes the database server specified by the database server group server from the global catalog The database server is removed from all participating replicates All replication data is purged from the send queues for the database server specified Enterprise Replication removes the global catalog from the replication server server and shuts down on that server Enterprise Replication does not broadcast the cdr_delete_serv call to other replication servers Therefore the call needs to be issued twice as follows 1 Connect to the replication server that needs to be deleted serverA and issue cdr_delete_serv to purge its catalog and delete all queued data 2 Connect to another replication
249. ormation about the buffers that form the acknowledgment queue When the target database server applies transac tions it sends an acknowledgment to the source database server When the source database server receives the acknowledgment it can then delete those transactions from its send queue For information on the columns of the syscdrack_buf table refer to Columns of the Buffer Tables on page B 4 SMI Tables for Enterprise Replication B 5 syscdrack_txn syscdrack_txn The syscdrack_txn table contains information about the acknowledgment queue When the target database server applies transactions it sends an acknowledgment to the source database server When the source database server receives the acknowledgment it can then delete those transactions from its send queue The acknowledgment queue is an in memory only queue That is it is a volatile queue that is lost if the database server is stopped For information on the columns of the syscdrack_txn table refer to Columns of the Transaction Tables on page B 3 syscdrctrl_buf The syscdrctrl_buf table contains buffers that provide information about the control queue The control queue is a stable queue that contains control messages for the replication For information on the columns of the syscdrctrl_buf table refer to Columns of the Buffer Tables on page B 4 syscdrctrl_txn The syscdrctrl_txn table contains information about the control queue The
250. ou choose Start Group Enterprise Replication begins capturing data from the logical log and transmitting captured data to replicates To start a group using the CLU refer to cdr start group on page 11 66 Inactive When a replicate is in inactive state no database changes are captured trans mitted or processed When you first define a replicate group the replicate group assumes the state of the replicates in the replicate group Therefore if the replicates are inactive the replicate group is inactive To change the state of a replicate group from active to inactive choose Group Stop Group When you choose Stop Group Enterprise Replication stops capturing data from the logical log To stop a group using the CLU refer to cdr stop group on page 11 70 8 22 Guide to Informix Enterprise Replication Changing the State of a Group Quiescent When you choose Group gt Stop Group the group enters a quiescent state No more database changes are captured for any replicate in the replicate group However activity continues until all changes on transactions that are already committed are delivered Only complete transactions are delivered No changes from a transaction that is committed after Stop Group are delivered The quiescent state is a temporary state You cannot control the quiescent state from the Replication Manager Suspend When you choose Suspend Group the replicate group enters the suspend state
251. ou must declare the database servers to Enterprise Replication as follows 1 Decide where the send queue should go The send queue location is one of the options of cdr define server If you do not specify a location for the send queue it defaults to root dbspace This example uses the default Declare the hill database server to Enterprise Replication urban gt cdr define server init g_hill When you define a server for Enterprise Replication you must use the name of the server group rather than the database server name Verify that the definition succeeded You can use one of the following actions m Use the CLU utility cdr list server to list existing Enterprise Replication servers m The first Enterprise Replication definition on a database server creates a syscdr database Use DB Access and choose Database gt Select to verify that syscdr is present The syscdr database is not designed to provide information about Enterprise Replication to users it holds information that the database server uses to manage Enterprise Replication Infor mation about the status of Enterprise Replication is in the sysmaster database tables that Appendix B SMI Tables for Enterprise Replication discusses Command Line Utility 11 17 Define Replicates 4 Declare the second database server lake to Enterprise Replication urban gt cdr def ser c lake init sync g_hill g_lake The connect option allows you to declare g_lake
252. ounts cdr modify group sequential accounts 11 54 Guide to Informix Enterprise Replication car modify replicate cdr modify replicate The cdr modify replicate command modifies replicate attributes Syntax cdr modify replicate replicate Conflict Options p 11 28 participant Connect Option p 11 8 Frequency Options p 11 14 Special Options p 11 57 Element Purpose Restrictions Syntax participant Name of a participant in the The participant must be a Participant Name replication member of the replicate pil replicate Name of the replicate to modify The replicate name must exist Identifiers p 8 8 Usage The cdr modify replicate command modifies a replicate You can change the attributes of a replicate or of one or more participants in the replicate You can also change the mode of a participant If the command does not specify participants the changes apply to all participants in the replicate For attribute information see cdr define replicate on page 11 27 To add or delete a participant see cdr change replicate on page 11 22 If you change the conflict resolution rule with cdr modify replicate you must also explicitly state SCOPE parameter even if the SCOPE value does not change Command Line Utility 11 55 car modify replicate Restrictions The attributes for cdr modify replicate are the same as the attributes for cdr define replicate with the fo
253. p on a target database server you can recover the data from the ATS files However it might be easier to unload the data from the source and apply that data to the target database Preparing Consistent Data In most cases preparing consistent data simply requires that you decide which of your databases has the most accurate data and then copy that data onto the target database If the target database already has data for data consistency you must remove that data before adding the copied data For copying data you can use the following tools The High Performance Loader HPL The onunload and onload utilities The dbexport and dbimport utilities The UNLOAD and LOAD statements Preparing Data for Replication 6 3 Shadow Columns When you unload and load data you must use the same type of utility for both the unload and load operations For example you cannot unload data with the onunload utility and then load the data with a LOAD statement Shadow Columns In an update anywhere replication you must provide for conflict resolution When you create a table that uses the time stamp or time stamp plus stored procedure conflict resolution rule you must define shadow columns with the WITH CRCOLS clause The shadow columns cdrserver and cdrtime contain information that Enterprise Replication uses for conflict resolution If a table does not have shadow columns you must use the ignore conflict resolution rule For more information
254. p_id salary FROM employee WHERE exempt N Insert Followed by a Delete dallas_office phoenix_office BEGIN WORK A INSERT INTO employee VALUES 927 Smith DELETE FROM employee WHERE emp_id 927 COMMIT WORK Figure 7 3 shows a transaction that takes place at the Dallas office Enterprise Replication uses the logic in Figure 7 4 on page 7 8 to evaluate whether any information is sent to the destination database server at the Phoenix office Enterprise Replication Processes 7 7 Evaluating Replication Examples Figure 7 4 Insert Followed by a Delete Evaluation Logic Replicate Final Replicate Primary Key Send to Destination Initial Image Evaluates Image Evaluates Changed Database Server INSERT TorF DELETE Tor F yes or no nothing Enterprise Replication determines that the insert followed by a delete results in no replication operation therefore a replication message is not sent In Figure 7 5 Enterprise Replication uses the logic in Figure 7 6 to evaluate whether any information is sent to the destination database server Figure 7 5 Insert Followed by dallas_office phoenix_office an Update SELECT emp_id salary FROM employee WHERE exempt N BEGIN WORK BEGIN WORK INSERT INTO employee VALUES 927 Smith N INSERT INTO employee UPDATE employee VALUES 927 Jones SET Iname Jones WHERE emp_id 927 COMMIT WORK
255. pacity 5 7 row information 7 20 setting 3 21 Spooling information 8 19 SQL code Intro 12 SQL statements complex 5 10 limitations 5 3 sqlhosts information INFORMIXSQLHOSTS environment variable E 2 on UNIX 3 4 8 6 11 12 12 4 on Windows NT 3 4 8 6 E 2 Stable queue use in distribution process 7 11 Start data delivery for a replicate 8 15 for replicate 11 67 12 40 for replicate group 8 22 11 66 12 39 Start Enterprise Replication 11 64 Start replication 12 38 Status information SMI tables B 1 Stop data delivery for a replicate 12 43 for replicate group 12 42 Stop Enterprise Replication 11 68 12 41 Stored procedure arguments 7 18 example D 3 SPL only 2 16 Stored procedure conflict resolution rule definition of 7 17 evaluating blob data 5 13 stores_demo database Intro 5 superstores Intro 5 superstores_demo database Intro 5 Suspend data delivery for database server 12 46 for replicate 12 45 for replicate group 12 44 Suspend state definition of 8 16 8 23 Synchronization of operating system times 5 9 Synchronize clocks 7 16 Synchronizing data using DB Access 6 10 using ESQL C 6 10 using onunload and onload utilities 6 5 Synchronous data replication definition of 1 3 syscdr database description of 11 17 System requirements database Intro 4 software Intro 4 System monitoring interface SMI tables list of B 1 syscdrack_buf B 5 syscdrack_txn B 6 syscdrctrl_buf B 6 syscdrctrl_txn B 6 syscdrerror B 7 B 16
256. participant replicate Specifies the rows and columns to replicate Name of a participant in the replication Name of the new replicate Usage See Restrictions on the SELECT Participant Statement on page 11 11 Modifier p 11 11 The participant must exist Participant p 11 9 The replicate name must be Identifiers p 8 8 unique To be useful a replicate must include at least two participants You can define a replicate that has only one participant but before you can use that replicate you must use cdr modify replicate to add more participants Command Line Utility 11 27 car define replicate Conflict Options The conflict options specify how Enterprise Replication should resolve conflicts among data that arrive at the database server Conflict Options Back to cdr define replicate p 11 27 Back to cdr modify replicate p 11 55 gt conflict ignore procedure optimize timestamp 3 procedure pa optimize scope EU row EA transaction Element Purpose Restrictions Syntax procedure Stored procedure for conflict The procedure must exist Identifiers p 8 8 resolution For a discussion of conflict resolution refer to Evaluating Data for Repli cation on page 7 4 11 28 Guide to Informix Enterprise Replication cdr define replicate The conflict options have the meanings shown in the following table Options Long Form Short Form
257. pe table on usa SELECT from stores usa call_type 3 36 Guide to Informix Enterprise Replication Update Anywhere Example Using ERM Update Anywhere Example Using ERM This example uses ERM to perform the same simple update anywhere repli cation that the Update Anywhere Example Using the CLU on page 3 9 shows Changing to Expert Mode The only replication option available in nonexpert mode is primary target replication You must switch to expert mode to do update anywhere replication For instructions on how to switch between expert and nonexpert modes refer to Choosing Nonexpert Mode on page 3 23 Creating an Update Anywhere Replicate This section creates a replicate that causes replication of any change to the state table of the stores database on any of the database servers in the replicate This replicate is equivalent to the replicate in Update Anywhere Example Using the CLU on page 3 9 except that the table replicated is state instead of stock Choosing a Replicate Name and Type Select Replicate gt Define Replicate ERM displays the introductory page of the Define Replicate wizard Click Next On the next page enter a name for the replicate rep 4 Click the Update Anywhere option button and then click Next Replication Examples 3 37 Creating an Update Anywhere Replicate Specifying a Conflict Rule In update anywhere replication conflicts can occur when two users update the same row
258. phical display of the replication hierarchy Figure 8 10 shows a hierar chical view In this view a solid circle represents a root server the smaller circle with a network represents a nonroot server and the circle on two petals represents a leaf server gt Figure 8 10 IR Hierarchical Routing View Hierarchical View Replication System For information about the menus that are available when the Hierarchical Routing View window is active refer to Hierarchical View Menus on page 8 38 Enterprise Replication Menus 8 27 Changing to Primary For information about Enterprise Replication topologies refer to Enterprise Replication Topologies on page 2 3 Changing to Primary In nonexpert mode this option lets you change which server in a primary target replication is the primary server When you select a new server to be the primary server the previous primary server becomes a target server To change a server to primary select a server and then choose Server gt Change to Primary In expert mode multiple primary servers can replicate information to a target server Use this option to change a target server to a primary server To change a primary or secondary server with CLU refer to cdr modify replicate on page 11 55 Changing to Target gt Important This option is available only in expert mode In expert mode a replicate can have multiple primary servers Use Se
259. plicate group or replicate name The name of the source database server syscdrqueued syscdrqueued The syscdrqueued table contains data queued information Column Type Description servername char 128 Sending to database server name name char 128 Replicate group or replicate name bytesqueued decimal 32 0 Number of bytes queued for the server servername syscdrrecv_buf The syscdrrecv_buf table contains buffers that provide information about the data receive queue When a replication server receives replicated data from a source database server it puts this data on the receive queue for processing On the target side Enterprise Replication picks up transactions from this queue and applies them on the target For information on the columns of the syscdrrecv_buf table refer to Columns of the Buffer Tables on page B 4 syscdrrecv_txn The syscdrrecv_txn table contains information about the data receive queue The receive queue is an in memory queue When a replication server receives replicated data from a source database server it puts this data on the receive queue picks up transactions from this queue and applies them on the target For information on the columns of the syscdrrecv_txn table refer to Columns of the Transaction Tables on page B 3 SMI Tables for Enterprise Replication B 11 syscarrepl syscdrrepl Column repIname grpname replstate freqtype freqmin freqhour freqday
260. ppropriate server regardless of a network or system failure In the event of a failure the message queue stores data until the network or system is operational The message queue replicates data efficiently with a minimum of data copying and sending Applying Replicated Data Enterprise Replication uses a data synchronization process to apply the repli cated data to target database servers The target database servers acknowledge receipt of a message when the message is safely stored A message is safely stored when it is in a stable recoverable queue or when it isin the target database The data synchronization process ensures that trans actions are applied at the target database servers in the same order as they were committed on the source database server Enterprise Replication Features 2 19 Replication Examples In This Chapter Environment for the Replication Examples Terminology Primary Target Example Using the CLU Preparing for a Primary Target Replication Cause a Replication Do Not Cause a Replication Update Anywhere Example Using the CLU Preparing for an ee Sen Cause a Replication Changing the stock Table on de usa Daba Served Updating the stock Table on the japan Database Server Hierarchy Example Using the CLU Preparing for a Hierarchy Example Defining a Hierarchy Primary Target Example Using ERM ae Removing Previously Defined Replication Servers Deleting Previously Defined Replicatio
261. ptured and propagated Step 8 Suspend or Remove Database Servers Some months later the database administrator is informed that the computer bangor must be taken out of service for maintenance The administrator has several choices m Suspend the bangor database server for both milpitas and ames m Remove bangor as a participant from employeeinfo m Delete the database server bangor from the global catalog D 8 Guide to Informix Enterprise Replication Step 9 Stop Replication with cdr_stop_reol Method 1 Uses the cdr_suspend_serv Call If the database administrator monitors the queues on bangor after the suspends to ames and milpitas are issued and ensures that the queues have emptied properly no data intended for bangor is lost All updates for bangor are queued at the respective origins either ames or milpitas When bangor returns to operation and is resumed at ames and milpitas all updates that occurred during the bangor outage are propagated to bangor No resynchro nization is necessary The database server is suspended on both of the other database servers ames and milpitas The replication is still in the active state Method 2 or 3 Assumes bangor Is Resynchronized These methods assume that bangor is resynchronized before it is re added to the employeeinfo replicate on ames and milpitas Method 2 uses cdr_participate_repl to remove bangor as a participant in the employeeinfo replicate Method 3 uses cdr_delete
262. r nothing INSERT with final row image nothing DELETE with initial row image nothing DELETE with initial row image and INSERT with final row image UPDATE with final row image DELETE with initial row image INSERT with final row image nothing Comments Net change of trans action results in no replication Inserts final data of transaction Final evaluation determines no replication Net result of trans action is delete Net change of trans action results in no replication Ensures old primary key does not replicate Simple update Row no longer matches replicate definition Row now matches replicate definition No match exists and therefore no replication Evaluating Replication Examples The table in Figure 7 2 illustrates how Enterprise Replication evaluates the row image type INSERT UPDATE DELETE the results of evaluating the replicate WHERE clause for both the initial and final image and whether the primary key changes as a result of the transaction Tip The evaluation logic in Figure 7 2 on page 7 6 assumes that the source and the destination tables are synchronized If the tables are not synchronized anomalous behavior could result Evaluating Replication Examples Figure 7 3 Figure 7 5 on page 7 8 and Figure 7 7 on page 7 9 show three examples of how Enterprise Replication uses logic to evaluate transactions for potential replication Figure 7 3 SELECT em
263. r Getting Started manual for a list of supplementary titles Software Dependencies This manual assumes that you are using one of the following database servers m Informix Dynamic Server Version 7 31 m Informix Dynamic Server 2000 Version 9 2 You also need to install Informix Connect I Connect is part of the database server product bundle but it has a separate install procedure Using Enterprise Replication Manager To use Enterprise Replication Manager with Dynamic Server Version 7 31 install Informix Enterprise Command Center IECC From IECC choose Tools gt Enterprise Replication Manager To use Enterprise Replication Manager with Dynamic Server Version 9 2 install ERM and the proper connectivity tools For information about preparing ERM for Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of this chapter 4 Guide to Informix Enterprise Replication Assumptions About Your Locale Assumptions About Your Locale Informix products can support many languages cultures and code sets All culture specific information is brought together in a single environment called a Global Language Support GLS locale This manual assumes that you use the U S 8859 1 English locale as the default locale The default is en_us 8859 1 ISO 8859 1 on UNIX platforms or en_us 1252 Microsoft 1252 for Windows NT environments This locale supports U S Eng
264. ration wizards List of Open Windows Each time you open a new document window ERM adds an entry to the numbered list at the bottom of the Window menu To activate a specific window choose its entry from the numbered list 8 34 Guide to Informix Enterprise Replication The Help Menu The Help Menu The Help menu provides access to the on line help and information about Enterprise Replication The Help menu has the following options m Help Topics m Using Help m Contacting Informix m About Replication Manager Help Topics The Replication Manager provides on line help for both reference help and context sensitive help Reference help includes topics such as What is a Replicate and Defining a Primary Replicate Context sensitive help provides a concise answer that describes the function of a menu item or icon that you are asking about Accessing Reference Help To access reference help choose Help Help Topics Figure 8 12 shows an example of a Help Topics dialog box Enterprise Replication Menus 8 35 Help Topics Help Topics Enterprise Replication Manager Help Active replicate group state Active replicate state Add Participant s wizard Add Replicate s wizard Adding objects to current system replication script objects Applier Summary dialog box Apply Safely option Asynchronous data replication Attributes database server group participant replicate viewing and modifying Browse Server dialog b
265. re Dependencies Assumptions About Your Locale Demonstration Databases New Features Documentation Contendo Typographical Conventions Icon Conventions ee Command Line Conventions Sample Code Conventions Additional Documentation On Line Manuals Printed Manuals On Line Help Error Message Documentation Documentation Notes Release Notes Machine Notes Related Reading a Compliance with Industry Seshidards Informix Welcomes Your Comments o ONA uae BW Q y E O mememe DO O OTF KF FP WW HN CO Section Introducing Informix Enterprise Replication Chapter 1 Data Replication Overview InvThis Chapter s s ecs dsd a Hg e Sos 1 3 Data Replication Types A eS 1 3 Synchronous Data Replication La A a a Gt Es 1 3 Asynchronous Data Replication 2 1 1 4 Data Replication Capture Mechanisms 1 5 Trigger Based DataCapture 2 we 1 6 Trigger Based Transaction Capture 1 6 Log Based Data Capture n 1 ee 1 8 Informix Enterprise Replication Features 1 1 8 High Performance a o 1 9 High Availability 2 2 2 ee 1 9 Consistent Information Delivery 110 Flexible Architecture 1410 Easy Centralized Administration 111 How Enterprise Replication Replicates Data 112 Chapter 2 Enterprise Replication Features In This Chapter ty Gin we Sat lap A
266. re not replicated to the primary The primary target model can distribute information using one primary database replicating to several secondary databases or collect information using several primary databases replicating to a single secondary m Update anywhere All databases have read and write capabilities Updates are applied at all databases The update anywhere model provides the greater challenge in asynchronous replication For example if a replication system contains three replication sites that all have read and write capabilities update conflicts occur when the sites try to update the same data at the same time Update conflicts must be detected and resolved so that the data elements eventually have the same value at every site Asynchronous replication is the more common type of data replication in open system environments because it protects against the system and network failures Data Replication Capture Mechanisms Asynchronous data replication updates the target databases after the primary database has committed the change Several mechanisms can be used to capture data in asynchronous replication The most frequently used data replication capture mechanisms are m Trigger based data capture m Trigger based transaction capture m Log based capture Data Replication Overview 1 5 Trigger Based Data Capture Trigger Based Data Capture A trigger is associated with a piece of data When a change is made to the
267. re versions of our manuals we want to know about any corrections or clarifications that you would find useful Include the following information m The name and version of the manual that you are using m Any comments that you have about the manual m Your name address and phone number Send electronic mail to us at the following address doc informix com The doc alias is reserved exclusively for reporting errors and omissions in our documentation We appreciate your suggestions 16 Guide to Informix Enterprise Replication Introducing Informix Enterprise Replication Chapter 1 Data Replication Overview Chapter 2 Enterprise Replication Features Chapter 3 Replication Examples Data Replication Overview In This Chapter Data Replication Types j Synchronous Data Replication Asynchronous Data Replication Data Replication Capture Mechanisms Trigger Based Data Capture Trigger Based Transaction Capture Log Based Data Capture Informix Enterprise Replication Features High Performance High Availability o Consistent Information Delivery Flexible Architecture Replication Models Network Topologies Data Types Operating Modes Easy Centralized Administration How Enterprise Replication Replicates Data 1 3 1 3 1 3 1 4 1 5 1 6 1 6 1 2 Guide to Informix Enterprise Replication In This Chapter Sharing corporate data is an important aspect of day to day business oper
268. record is updated multiple times the changes are applied to the remote databases in the same order as on the primary database and applied only once at the target database server If update conflicts occur Enterprise Replication provides built in automatic conflict detection and resolution You can configure the way conflict resolution behaves to meet the needs of your database Flexible Architecture A replication system should not impose model or methodology restrictions on the enterprise A replication system should allow replications based on specific business and application requirements Replication Models Enterprise Replication supports both primary target and update anywhere replication models Network Topologies Enterprise Replication supports the following network topologies m Fully interconnected Continuous connectivity between all participating database servers m Hierarchical tree A parent child configuration that supports continuous and inter mittent connectivity m Forest of trees Multiple hierarchical tree that connects at the root database servers For more information see Enterprise Replication Topologies on page 2 3 1 10 Guide to Informix Enterprise Replication Easy Centralized Administration Data Types Enterprise Replication supports all built in Informix data types across heter ogeneous hardware Enterprise Replication also supports the Global Language Support GLS feature which a
269. remove the replication servers in either of the following two ways m If you are using practice database servers completely re initialize each database server as follows a Use oninit iy to reinitialize the database and erase all previous data o Re create the stores databases as shown in the final bullet of Environment for the Replication Examples on page 3 3 m If you cannot re initialize the servers delete each replication server You can delete all the servers from the s1 computer the host for g_usa For each server except usa issue the following commands cdr delete server server_group_name cdr delete server c server_name server_group_name For example cdr delete server g_japan cdr delete server c japan g_japan Finally delete the replication server on usa cdr delete server g_usa The preceding commands remove only the definition of the replication servers They do not halt the database server remove any other databases or negate the changes that you made to the stores databases in the earlier examples Replication Examples 3 17 Defining the First Replication Server After you remove the definitions of the replication servers continue with Defining the First Replication Server on page 3 18 Using Previously Defined Replication Servers The examples in Preparing for a Primary Target Replication on page 3 6 and Preparing for an Update Anywhere Replication on page 3 9
270. replication groups You do not need to be user informix to use this command Example The following example displays a list of the groups on the current server cdr list group Sample output GROUP SEQ PARTICIPANTS weekly Y repl rep2 rep3 NewGroup N one three seven Command Line Utility 11 47 cdr list replicate cdr list replicate The cdr list replicate command displays information about the replicates on the current server Syntax cdr list replicate Usage The cdr list replicate command displays information about replicates If no replicates are named the command lists all replicates on the current server If one or more replicates are named the command displays detailed infor mation about those replicates You do not need to be user informix to use this command Example The following example displays a list of the replicates on the current server cdr list replicate The output from the previous command might be the following REPLICATE STATE CONFLICT FREQUENCY OPTIONS myrep INACTI ignore immediate transaction ris ats rOne ACTIVE ignore immediate transaction ris ats rTwo ACTIVE ignore immediate transaction ris ats 11 48 Guide to Informix Enterprise Replication Example The STATE column can include the following values m ACTIVE replicate active m DEFN FAI definition failure m INACT inactive m PEND pending delete m QUIES quiescent m SUSP suspend The following examp
271. rise Replication uses You can use this information about threads when you evaluate memory use Number of Threads Thread Description 1 Performs physical I O from logical log 1 Verifies potential replication and sends applicable log record entries to Enterprise Replication fan out thread 1 Receives log entries and passes entries to evaluator thread n Evaluates log entry to determine if it should be replicated n is the number of evaluator threads specified by CDR_EVALTHREADS This thread also performs transaction compression on the receipt of COMMIT WORK and sends completed replication messages to the queue process 1 of 2 5 8 Guide to Informix Enterprise Replication Number of Threads 1 1 1 per connection 1 per connection 2 n 2 n CPUs Environmental Considerations Thread Description Parses all WHERE clauses for replicate definitions Keeps track of current buffers in use Sending thread for site Receiving thread for site Accepts acknowledgments from site At least 2 up to a maximum of the number of active connections Read TEXT and BYTE data from spooled receive queue At least 2 up to a maximum of the number of active connections This thread is created for parallel processing The thread synchro nizes data receives the replication message and applies it to a local instance The thread also performs conflict resolution and inserts information into delete tables if required
272. ronments use the Informix Find Error utility To display this utility choose Start gt Programs gt Informix from the Task Bar Instructions for using the preceding utilities are available in Answers OnLine Answers OnLine also provides a listing of error messages and corrective actions in HTML format 14 Guide to Informix Enterprise Replication UNIX WIN NT Documentation Notes Release Notes Machine Notes Documentation Notes Release Notes Machine Notes In addition to printed documentation the following sections describe the on line files that supplement the information in this manual Please examine these files before you begin using your database server They contain vital information about application and performance issues The following on line files appear in the INFORMIXDIR release en_us 0333 directory On Line File Purpose EREPDOC_9 2 SERVERS_9 2 IDS_9 2 The documentation notes file for your version of this manual describes topics that are not covered in the manual or that were modified since publication The release notes file describes feature differences from earlier versions of Informix products and how these differences might affect current products This file also contains information about any known problems and their workarounds The machine notes file describes any special actions that you must take to configure and use Informix products on your computer Machine notes are nam
273. ror messages Intro 14 Index 3 ABCDEFGH I Message queue description 7 11 planning space for 5 6 See also Receive queue See also Send queue Mode field in CDR_plist 12 5 of participant 11 55 set 11 10 12 27 12 29 N New features of this product Intro 6 O ONCONFIG file configuration parameters A 1 setting DBSERVERNAME 11 12 12 3 A 1 On line help Intro 14 On line manuals Intro 13 onstat command F 1 onunload and onload utilities synchronizing data 6 3 6 5 Operational limitations 5 3 Optical devices not supported 5 11 Optimized mode stored procedure 7 19 P Participant adding to replicate 8 14 9 15 11 22 12 32 change mode 12 27 12 29 defining 12 14 definition of 2 11 deleting from replicate 8 14 11 22 12 32 owner option 8 29 11 10 primary option 11 10 read only option 11 10 syntax 11 9 4 Guide to informix Enterprise Replication Participant modifier description 11 9 restrictions 5 15 11 11 syntax 11 11 user defined types 5 15 Platform icons Intro 9 Primary participant 8 17 Primary target replication system 4 3 Printed manuals Intro 14 Processes evaluating data for replication 7 11 evaluating distinct times 7 4 synchronizing data using conflict resolution 7 12 Product icons Intro 9 Program group Documentation notes Intro 15 Release notes Intro 15 Properties participant viewing 8 19 replicate group viewing replicate 8 24 replicate viewing 8 17 server viewing 8
274. roup 8 21 11 20 12 31 ANSI compliance level Intro 16 API function cdr_connect 12 10 cdr_define_group 12 11 cdr_define_repl 12 14 cdr_define_serv 12 18 cdr_delete_group 12 20 cdr_delete_repl 12 21 cdr_delete_serv 12 22 cdr_error_reviewed 12 23 cdr_modify_group 12 24 cdr_modify_repl 12 25 cdr_modify_replmode 12 27 cdr_modify_serv 12 28 cdr_modify_servmode 12 29 cdr_move_errortab 12 30 cdr_participate_group 12 31 cdr_participate_repl 12 32 cdr_prune_errors 12 33 cdr_prune_single_error 12 34 cdr_resume_group 12 35 cdr_resume_repl 12 36 cdr_resume_serv 12 37 cdr_start_cdr 12 38 cdr_start_group 12 39 cdr_start_repl 12 40 cdr_stop_cdr 12 41 cdr_stop_group 12 42 cdr_stop_repl 12 43 cdr_suspend_group 12 44 cdr_suspend_repl 12 45 cdr_suspend_serv 12 46 list of 12 8 structure definitions 12 5 Arguments in stored procedures 7 18 Asynchronous data replication definition of 1 4 1 5 ATS See Aborted transaction spooling Begin work without replication 6 9 BLOB See Simple large object and smart large object Blobspace 5 11 Boldface type Intro 8 BYTE data distributing 5 14 c Canonical format 11 30 12 16 Capacity planning for delete tables 5 7 logical log records 5 5 spooling directories 5 7 A BC D E F GH Capture mechanisms log based data capture 1 8 Cascading deletes implementation of 7 20 CDR_DSLOCKWAIT configuration parameter A 2 CDR_EVALTHRE
275. roup_id source_id key_acked_srv key_acked_lgid key_acked_lgpos Type integer integer integer integer integer integer Description Server ID of the destination server The ID that Enterprise Replication uses to identify the group for which this information is valid Server ID of the server from which the data originated Last key for this group that was acknowledged by this destination Logical log ID Logical log position 1 of 2 SMI Tables for Enterprise Replication B 9 syscarq Column Type key_acked_seq integer tx_stamp_1 integer tx_stamp_2 integer syscdrq Column Type srvid integer repid integer srcid integer srvname char 128 replname char 128 srcname char 128 B 10 Guide to Informix Enterprise Replication Description Logical log sequence Together with tx_stamp2 forms the stamp of the last transaction acknowledged for this group by this destination Together with tx_stamp1 forms the stamp of the last transaction acknowledged for this group by this destination 2 of 2 The syscdrq table contains information about Enterprise Replication queues Description The identifier number of the database server The identifier number of the replicate The server ID of the source database server In cases where a particular server is forwarding data to another server srvid is the target and srcid is the source that started the transaction The name of the database server Re
276. rprise Replication from the command line on your UNIX or Windows NT operating system This chapter has the following sections m Definitions List of commands Command line abbreviations Option abbreviations Backslash use Connect clause Participant Participant modifier Server group Return codes O oO O O O O oO OO O DO Time formats m Example of a command line script m Descriptions of each individual command line command m Definitions This section defines the terminology and conventions used in the descrip tions of the CLU The CLU has many variations such as cdr define group and cdr resume replication Although technically Enterprise Replication has only one command line utility cdr this chapter treats each variation of the CLU as if it were a separate command Command Line Utility 11 3 Each command follows the same approximate format with the following components m Command and its variation The command specifies the action that should be taken m Options The options modify the action of the command Each option starts with a minus or a double minus m Target The target specifies the Enterprise Replication object that should be acted upon m Other objects Other objects specify objects that are affected by the change to the target If you enter an incorrect cdr command at the command line prompt the database server returns a usage message that summarizes the cdr commands For a more detai
277. rprise Replication error information Replicate group information Detailed information about replicate groups Participant information Contents of the Enterprise Repli cation progress tables Queued data information brief Queued data information detailed Reference page B 5 page B 6 page B 6 page B 6 page B 7 page B 7 page B 8 page B 8 page B 9 page B 10 page B 11 1 of 2 Enterprise Replication Queues Table syscdrrecv_buf syscdrrecv_txn syscdrrepl syscdrs syscdrsend_buf syscdrsend_txn syscdrserver syscdrsync_buf syscdrsync_txn syscdrtx syscdrtxproc B 2 Guide to Informix Enterprise Replication Description Buffers in the receive queue Transactions in the receive queue Replicate information Server information Buffers in the send queue Transactions in the send queue Database server information Buffers in the synchronization queue Transactions in the synchronization queue Transaction information Transaction processes information Enterprise Replication Queues Reference page B 11 page B 11 page B 12 page B 13 page B 14 page B 15 page B 15 page B 16 page B 16 page B 17 page B 17 2 of 2 One group of sysmaster tables shows information about Enterprise Repli cation queues The sysmaster database reports the status of these queues in the tables that have the suffixes _buf and _txn The name of each table that describes an Enterprise Replication q
278. rror occurs See Using the Stored Error Information on page C 1 Usage The cdr_participate_group function modifies the replicate group group by adding or removing replicates If the value of op is A_ADD the function adds the replicates in the repls list to the group If the operation is type A_REMOVE the function removes the replicates in the repls list from the group If the function removes the last participant from the group the function also removes the group from the global catalog Removing a replicate from a group does not destroy the replicate or change its state The state of the replicate state remains the same as the state of the replicate group from which the replicate was removed API Functions 12 31 cdr_participate_reol cdr_participate_repl The cdr_participate_repl function adds or removes participants from a replicate Syntax include cdrapi h int cdr_participate_repl repl participants op which char repl uintl Op CDR_plist participants void which repl is the replicate name participants is the list of participants op is the operation type A_ADD or A_REMOVE which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage The cdr_participate_repl function modifies the replicate rep by adding or removing the participants in the participants list If the value of op is A_ADD the f
279. rrors depending on the conflict resolution rule and scope Enterprise Replication Processes 7 21 In addition the following trigger operations behave differently when they execute on the target database server All replicated columns are considered to be modified if the database operation is updated including the values for some of the columns that might not have been modified All update triggers defined on replicated columns are invoked If an update trigger is defined on table tab1 and the following command is executed UPDATE tabl SET a a 1 on the source database server the command affects all rows in table tab1 If any before action exists for the update trigger the before action trigger is executed once for this statement any for each row is executed once for each row processed and any after action is executed once for the statement However if the same update trigger is defined on the target table and the same command is executed on the source database server the following results occur all before for each row and after actions are executed once for each row that the target database server is processing Enterprise Replication Menus ln This Chapter sie td a a a a Bes 8 5 General Information py a A de 8 6 Preparing to Use the Replication Manager Ste Se a Sr ate eons 8 6 Opening the Replication Manager 2 8 6 Understanding Server Terminology 87 Using M des ui ee
280. rrors that occurred within the time range are deleted If the reviewed_only flag is nonzero only errors that match the specified time criteria and that have been reviewed are deleted For information about the severe error table refer to Severe Error Table on page 12 7 API Functions 12 33 cdr_prune_single_error cdr_prune_single_error The cdr_prune_single_error function prunes a single error from the severe error table Syntax include cdrapi h int cdr_prune_single_error origserver remote_seqnum char origserver long remote_seqnum origserver is the name of the database server group that includes the database server from which the error originated remote_seqnum is the remote sequence number value for the error that should be deleted Combined with origserver this number provides a unique key for every error Usage The cdr_prune_single_error function deletes a single error from the severe error table It uses the name of the originating server group and the sequence number from that database server to uniquely specify the error to be deleted The specified error is deleted from all database servers that participate in replication For more information about the severe error table refer to Severe Error Table on page 12 7 12 34 Guide to Informix Enterprise Replication cdr_resume_group cdr_resume_group The cdr_resume_group function resumes delivery of replic
281. rsion of Enterprise Replication does not support replication of smart large objects BLOBs and CLOBs Using GLS with Enterprise Replication An Enterprise Replication system can include databases in different locales with the following restrictions m When you define a database server for Enterprise Replication that server must be running in the English locale In other words the syscdr database on every Enterprise Replication server must be in the English locale m You can replicate only between databases that are in the same locale Setting Up Your Replication Environment 5 15 Using GLS with Enterprise Replication m Replication names can be in the locale of the database m Replication names might be displayed incorrectly by the Replication Manager The Replication Manager can run in any locale but it can run in only one locale at a time If the databases in your replication system are in multiple locales the names of some of the replicates might display incorrectly Codeset conversion with the GLS library requires only those codeset conversion files found in the INFORMIXDIR gls cv9 directory In addition ERM uses the UTF8 conversion and locale files database server installation and IECC setup For users of U S English locales should be taken care of automatically by the For users of U S English locales should be taken care of automatically by the eal Client SDK Informix Connnect installation and setup
282. rt mode This option lets you find the states of all servers in the replication environment without connecting to each individual server Choose Server gt Change State to open the dialog box The Server State dialog box in Figure 8 9 shows that replication of data from server usa to server boston is suspended However replication from boston to usa is active You can suspend replication in one direction without suspending replication in the other direction To change the status from Suspended to Active select the appropriate entry in the table and click Resume z Figure 8 9 Y Server y nver 2 ot Server State g denver Server State Dialog Box Active Suspended Unknown o Unknown 8 26 Guide to Informix Enterprise Replication Viewing the Replication Hierarchy When you open this dialog box only the status of replicates from denver the current connection as shown by the title bar to the other servers is known To find out the status of the Unknown entries select the entry and then click Query To suspend or resume a server using the CLU refer to cdr suspend server on page 11 77 and cdr resume server on page 11 63 To see the server states using the CLU refer to cdr list server on page 11 50 Viewing the Replication Hierarchy gt Important This option is available only in expert mode Select Server gt Hierarchical Routing to open a window that shows a gra
283. rticipant should be removed When ERM receives this command it immediately purges all data from the queues associated with the replicate and removes the replicate from the global catalog To remove a replicate with the CLU refer to cdr delete replicate on page 11 39 Important If you delete an active replicate Enterprise Replication cannot guarantee consistent tables Before deleting a replicate stop the replication and wait for the queues to empty Enterprise Replication Menus 8 13 Changing Replicate States Adding a Participant To add participant s to an existing replicate select the replicate and choose Replicate gt Add Participant s The Add Participant wizard appears and guides you through the steps for defining a replicate Adding a Participant on page 9 15 describes the Add Participant wizard To add a participant to a replicate with the CLU refer to cdr change replicate on page 11 22 Warning When you add a participant to an existing replicate you must synchronize the databases before you start replication with the new participant For information on how to synchronize your databases see Chapter 6 Preparing Data for Replication Removing a Participant To remove a participant from a replicate click the replicate to display the participants Select a participant and choose Replicate gt Remove Participant ERM asks you to verify that the participant should be removed To remove a parti
284. rver Menu Suspending and Resuming a Database Server Finding or Changing the Server State Viewing the Replication Hierarchy Changing to Primary Changing to Target E Starting and Stopping Enterprise Replication Stopping Replication Starting Replication Specifying Privileges Removing a Database Server koii P iaprse Replication 4 Reloading the Global Catalog Viewing Database Server Properties View Menu By Replicate and By Server Toolbar and Status Bar 8 2 Guide to Informix Enterprise Replication Window Menu Nonexpert Mode Expert Mode List of Open Windows The Help Menu s a Help Topics Accessing Reference Help Accessing Context Sensitive Help Using Help Contacting Informix About Replication Manager Hierarchical View Menus Replication Scripting View Menus 8 33 8 33 8 34 8 34 8 35 8 35 8 35 8 37 8 37 8 37 8 37 8 38 8 39 Enterprise Replication Menus 8 3 8 4 Guide to Informix Enterprise Replication WIN NT In This Chapter The Enterprise Replication Manager ERM is a Windows NT graphical user interface GUI provided to help you administer and monitor Enterprise Replication This chapter covers the function of each of the menu options The on line help provides additional information about various options The next chapter Chapter 9 Enterprise Replication Manager Wizards describes the ERM wizards
285. rver and cdrtime columns You must perform a level 0 archive after completion You can also use deluxe mode without replication to load data After a deluxe mode load you do not need to do a level 0 archive Deluxe mode also allows you to load TEXT and BYTE data and user defined types Using the onunload and onload Utilities You can use the onunload and onload utilities only to unload and load an entire table If you want to unload selected columns of a table you must use either unload or the HPL For more information about onunload and onload see the Informix Migration Guide Using the dbexport and dbimport Utilities If you need to copy an entire database for replication you can use the dbexport and dbimport utilities These utilities unload an entire database including its schema and then re create the database If you want to move selected tables or selected columns of a table you must use some other utility For more information about dbexport and dbimport see the Informix Migration Guide Using the UNLOAD and LOAD statements The UNLOAD and LOAD statements allow you to move data within the context of an SQL program Preparing Data for Replication 6 5 Blocking Replication If the table contains shadow columns you must perform the following two additional steps 1 Include the cdrserver and cdrtime columns explicitly in your statement when you unload your data 2 List the columns that you want to load in th
286. rver group attrs are the database server attributes to modify Usage The cdr_modify_serv function modifies the attributes attrs of the database server specified by the database server group server The same flag bits are supported as for cdr_define_serv except that you cannot modify the send queue A_SENDQ or the receive queue A_RECVO For a description of attributes see cdr_define_serv on page 12 18 12 28 Guide to Informix Enterprise Replication cdr_modify_servmode cdr_modify_servmode The cdr_modify_servmode function changes the mode of participants for a database server Syntax include cdrapi h int cdr_modify_servmode server mode char server uint4 mode server is the name of the database server group that includes the database server whose mode should be changed mode is the mode to use for all the participants for this database server It can be either A RDONLYMODE or A_PRIMARYMODE Usage The cdr_modify_servmode funtion changes the mode of all replicate participants for the specified database server The mode argument determines the mode for all participants of the database server A_PRIMARYMODE mode sets the participants to primary mode A_RDONLYMODE mode sets the participants to read only mode For A_RDONLYMOLE participants of replicates with conflict resolution that are not set to ignore are unchanged Participants already in the designated mode are unaffected API
287. rver gt Change to Target to change one of the primary servers to a target server Starting and Stopping Enterprise Replication Starting or stopping Enterprise Replication on a database server can cause your databases to get out of sychronization Informix recommends that you start and stop Enterprise Replication only when the databases are not in active use 8 28 Guide to Informix Enterprise Replication Specifying Privileges Stopping Replication To stop Enterprise Replication on a single database server instance select the database server and choose Server gt Stop Replication Stopping Enterprise Replication shuts down all Enterprise Replication threads and frees all in memory structures associated with that database server declared to Enter prise Replication No global catalog tables are destroyed with this command However if information is not stabilized all replication information is current and synchronized on all active replicates and replicate groups data might become inconsistent Stopping a database server can be useful if you need to resynchronize all tables that are to be replicated This command might also be appropriate when you want to stop Enterprise Replication in a database server To stop a replicate using CLU refer to cdr stop replicate on page 11 71 Starting Replication To start Enterprise Replication on a single database server select the database server on the main window and choose Server
288. s conflict resolution or encounters repli cation order problems For more information see Chapter 10 Diagnosing Enterprise Replication When floating point numbers are replicated transfer the numbers in canonical machine independent format This format is portable between operating systems but can lose accuracy 1 of 2 cdr define replicate Options Long Form Short Form Meaning firetrigger T The rows that this replicate inserts should fire triggers at the destination parallel p Process members in parallel The default is serial processing sequential S Process members sequentially 2 of 2 Examples The following example illustrates the use of cdr define replicate 1 cdr define repl conflict timestamp spl 2 scope tran ats newrepl Y 3 dbl iowa antonio tablel select from tablel A 4 db2 utah carlo table2 select from table2 Line 1 of the example specifies a primary conflict resolution rule of time stamp If the primary rule fails the stored procedure sp1 will be invoked to resolve the conflict Because no database server is specified here or on any later line the command connects to the database server named in the INFORMIXSERVER environment variable Line 2 specifies that the replicate has a transaction scope for conflict resolution scope and enables aborted transaction spooling The final item specifies the name of the replicate newrepl Line 3 defines the
289. s the dialog box that Figure 3 2 shows Figure 3 2 Server Not Initialized Dialog Box Replication Manager At this point you could click Yes and define g_italy However to parallel the example in Update Anywhere Example Using the CLU on page 3 9 g_usa should be defined first Click No Tip ERM might display one of the other database server groups Use the Select Server dialog box to select g_usa ERM displays the Select Server dialog box that Figure 3 3 shows Figure 3 3 Select Server Dialog Box 1 Click the down arrow to display the list of server groups 2 Select g_usa 3 Click OK Replication Examples 3 19 Defining the First Replication Server ERM displays the dialog box that Figure 3 4 shows Click Yes to define the replication server g_usa Figure 3 4 Server Not Initialized Dialog Box Replication Manager Q The Declare Server Dialog Box for NonExpert Mode ERM displays the Declare Server dialog box ERM has two modes expert mode and nonexpert mode When you first install ERM it is in nonexpert mode 3 20 Guide to Informix Enterprise Replication Defining the First Replication Server If you are in nonexpert mode Figure 3 5 shows the Declare Server dialog box Figure 3 5 Declare Server Dialog Box for Nonexpert Mode Declare Server In roas roas O To declare the usa replication server Remove the check mark from Use a Synchronization Server Change
290. s type of replication system no conflict detections or rules to resolve conflicts are necessary Primary target repli cation systems support the following business models Data dissemination Data consolidation Workload partitions Workflow replication Selecting Enterprise Replication Systems 4 3 Data Dissemination Data Dissemination Data dissemination supports a business need where data is updated in a central location and then replicated to read only sites This method of distri bution can be particularly useful for on line transaction processing OLTP systems where data is required at several sites but because of the large amounts of data read write capabilities at all sites would cripple the performance of the application Figure 4 1 illustrates data dissemination Taga Target bees Figure ata Dissemination Database Database in a Primary Target server ELE Replication System pd No Primary aoe Database server ca seve A En Read only Read only 4 4 Guide to Informix Enterprise Replication Data Consolidation Data Consolidation As businesses reorganize to become more competitive many choose to consolidate data into one central database server Data consolidation allows the migration of data from several database servers to one central database server In Figure 4 2 the remote locations have read write capabilities while the central database server is read only Pri Figure 4 2 Primary mney
291. scope invokerow spool invoke transpool primresolution B 12 Guide to Informix Enterprise Replication Type char 18 char 128 char 18 char 1 integer integer integer char 1 char 1 char 1 char 1 The syscdrrepl table contains replicate information Description Replicate name Replicate group name if replicate is part of a replicate group Null if replicate is not part of a replicate group Replicate state For possible values refer to cdr list replicate on page 11 48 Type of replication frequency C continuous I interval T time based M day of month W day of week Minute after the hour refresh should occur Null if continuous Hour refresh should occur Null if continuous Day of week or month refresh should occur Replication scope T transaction R row by row Y row spooling is invoked N no row spooling is invoked Y transaction spooling is invoked N no transaction spooling is invoked Type of primary conflict resolution I ignore T time stamp S stored procedure 1 of 2 Column secresolution storedprocname istriggerfire iscanonical syscdrs Type char 1 char 128 char 1 char 1 syscars Description Type of secondary conflict resolution S stored procedure Null not configured Name of stored procedure for secondary conflict resolution Null if not defined Y triggers are invoked
292. se Replication Manager Wizards 9 13 Reviewing Replicate Summary Reviewing Replicate Summary After you finish entering information about the participants in the wizard the ERM shows a summary of the attributes of the replicate that you just defined as Figure 9 9 shows Use the scroll bar to review all information for each database server that participates in your replicate Figure 9 9 Replicate Summary Window Replicate Summary If you discover errors click Cancel The wizard returns to the Define Replicate wizard where you can make the necessary change s If the summary is satisfactory click Create to create the replicate 9 14 Guide to Informix Enterprise Replication Adding a Participant Adding a Participant To add participant s to an existing replicate select the replicate from the main window of the Replication Manager and choose Replicate gt Add Participant s The Add Participant wizard page lists the steps necessary to add partic ipant s to an existing replicate The Add Participant wizard continues with the steps to add a participant that parallels the steps to define a replicate in Figure 9 5 on page 9 9 Figure 9 7 on page 9 12 and Figure 9 8 on page 9 13 Warning If you add a participant to an existing replicate you must synchronize the databases before you start replication with the new participant For information on how to synchronize your databases see Chapter 6 Preparing Data for R
293. sendq recvq atsdir ix myats risdir cdr list server g_miami g_miami 4 root g_boston leaf sendq recvq atsdir risdir 11 52 Guide to Informix Enterprise Replication car modify group cdr modify group The cdr modify group command modifies a replicate group Syntax cdr modify group Vo Toman repl_ group p 11 8 ho parallel sequential A Frequency Options p 11 14 Element Purpose Restrictions Syntax rep_grou Name of replicate group to The group must exist Identifiers p 8 8 p_sroup di P group group P modify Usage The cdr modify group command modifies the attributes of the replicate group rep_group Attributes of the group that are not specifically mentioned remain unchanged To add or delete replicates to a group use the cdr change group command on page 11 20 Command Line Utility 11 53 cdr modify group The options in cdr modify group have the meanings shown in the following table Options Long Form Short Form Meaning parallel p Process members of the group in parallel sequential S Process members of the group sequentially To change between parallel and sequential processing from ERM refer to Viewing Replicate Group Properties on page 8 24 Example The following example connects to the default server INFORMIXSERVER and modifies the replicate group accounts to process replication data sequen tially for replicates in acc
294. server CDR_idlist Servers time_t time unused void which db_server is the name of the database server group that includes the database server that should resume replication servers is an optional list of database server group names time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage The cdr_resume_serv function causes delivery of replication data including queued data to resume to the database server db_server from all servers included in the server group list servers If servers is null then repli cation resumes on all database servers API Functions 12 37 car_start_car cdr_start_cdr The cdr_start_cdr function restarts Enterprise Replication processing This function is valid only after a cdr_stop Syntax include cdrapi h int cdr_start_cdr Usage Use the cdr_start_cdr function to restart Enterprise Replication after it is stopped with cdr_stop_cdr When you issue cdr_start_cdr Enterprise Replication threads start and continue from the point at which they stopped Enterprise Replication resumes evaluation of the logical log if required for the instance of Enterprise Replication at the replay position The replay position is the position where Enterprise Replication stops evaluating the logical log when cdr_s
295. server command defines a database server group and all its members that is all database servers that are members of the database server group for Enterprise Replication Syntax Options cdr define server a ra p 11 35 connect server_ group sync sync_server init server_ group nonroot leaf Element Purpose Restrictions server_group Name of a server group to Must be the name of an existing Database Server declare for Enterprise server group Group p 11 12 Replication sync_server Name of server to use for Must bea server thatis registered Identifiers p 8 8 synchronization with Enterprise Replication The server must be on line Command Line Utility 11 33 cdr define server Long Form connect init leaf nonroot sync Usage Options Short Form gt E 11 34 Guide to Informix Enterprise Replication The long forms shown in the syntax diagram have the meanings and abbreviations shown in the following table Meaning Connects to the database server that is being defined If this option is omitted INFORMIXSERVER must be set to server_group Adds server_group to the replication system The server_group must be the same as the connection server Defines the server as a leaf server If neither leaf nor nonroot is specified the server is defined as a root server Defines the server as a nonroot server If neither leaf nor nonroot is specified the server is de
296. servers click the database server icon inthe upper left part of the ERM display Figure 3 8 shows the replication Servers At this point the only replication server is g_usa are 7 z Figure 3 8 Replication Manager g List of Replication Servers Replication Examples 3 23 Defining a Replication Server on italy Defining a Replication Server on italy To define the italy database server as a replication server select g_italy from the Server list box as Figure 3 9 shows Figure 3 9 et Replication Manager g_usa See Server File Replicate Group Server View Window Help List Box The italy database server is not yet a replication server ERM asks if you would like to bring up Enterprise Replication on g_italy Click Yes The second and subsequent replication servers must be linked to the first replication server g_usa so they can exchange information To create the connection between the replication servers choose g_usa as the synchroni zation server Set the spooling directory to tmp Figure 3 10 shows the finished dialog box Click OK 3 24 Guide to Informix Enterprise Replication Defining a Replication Server on italy PE Figure 3 10 Declare Server Declare the Second Replication Server After you declare the italy database server as a replication server the main ERM display shows the replication servers in your replication environment as Figure 3 11 shows s e Figure 3 11 os Replicati
297. sruname Number of transactions with source commit time on database server srvname greater than target commit time The syscdrtxproc table contains information about an Enterprise Replication transaction process Column servername txprocessed txcommitted txaborted Type char 128 integer integer integer Description Receiving from database server name Transaction processed from database server servername Transaction committed from database server servername Transaction aborted from database server servername 1 of 2 SMI Tables for Enterprise Replication B 17 syscartxproc Column rowscommitted rowsaborted txbadcnt B 18 Guide to Informix Enterprise Replication Type integer integer integer Description Rows committed from database server servername Rows aborted from database server servername Number of transactions with source commit time on database server servername greater than target commit time 2 of 2 Return Codes Definition of Return Codes The List of Return Values on page C 2 shows the return messages and codes that Enterprise Replication returns These messages are also documented in the cdrerr h file in INFORMIXDIR incl esql or INFORMIXDIR incl esql directory Using the Stored Error Information The following API functions include a pointer called which that points to a structure that contains error information when infor mation is available
298. ss appear in uppercase letters in a sans serif font This symbol indicates the end of one or more product or platform specific paragraphs 8 Guide to Informix Enterprise Replication This symbol indicates a menu item For example Choose Tools gt Options means choose the Options item from the Tools menu Tip When you are instructed to enter characters or to execute a command immediately press RETURN after the entry When you are instructed to type the text or to press other keys no RETURN is required Icon Conventions Throughout the documentation you will find text that is identified by several different types of icons This section describes these icons Icon Conventions Comment Icons Comment icons identify three types of information as the following table describes This information always appears in italics Icon Label Description Warning Identifies paragraphs that contain vital instructions cautions or critical information Important Identifies paragraphs that contain significant information about the feature or operation that is being described Tip Identifies paragraphs that offer additional details or shortcuts for the functionality that is being described Feature Product and Platform Icons Feature product and platform icons identify paragraphs that contain feature specific product specific or platform specific informat
299. ss to the shared SQLHOSTS registry key For information about network access conventions and file permissions see your Windows NT documentation E 2 Guide to Informix Enterprise Replication Preparing the SOLHOSTS Connectivity Information Preparing the SQLHOSTS Connectivity Information With Dynamic Server Version 7 31 use the IECC Add Database Servers wizard to prepare the SQLHOSTS connectivity information With Dynamic Server Version 9 2 refer to the documentation notes described in Documentation Notes Release Notes Machine Notes on page 15 of the Introduction for information about preparing the SQLHOSTS connectivity information Alternatively you can use the Windows NT program regedt32 Important Informix strongly recommends that you use one of the tools that Informix provides to prepare the SQLHOSTS connectivity information Unless you use extreme caution regedt32 can destroy the configuration not only of your Informix products but of your other applications To add connectivity information using regedt32 1 Run regedt32 2 Inthe Registry Editor window select the window for the HKEY_LOCAL_MACHINE subtree 3 Click the folder icons to select the SOFTWARE INFORMIX SOLHOSTS branch 4 With the SOLHOSTS key selected choose Edit gt Add Key 5 Inthe Add Key dialog box enter the name of the database server in the Key Name dialog box Leave the Class dialog box blank Click
300. st of the display If the summary is correct click Create Figure 3 27 Summary of repl4 Replicate Summary Replication Examples 3 43 Viewing the Replicate Viewing the Replicate When you click Create on the Replicate Summary page as Figure 3 27 on page 3 43 shows ERM creates the replicate and returns to the main ERM display as Figure 3 28 shows Click the replicate icon in the upper left part of the display ERM lists the replicates that you defined A Figure 3 28 o Replication Manager g japan List of Replicates Sfm a gt rep13 Ba g_italy target Active Active Inactive Boe Inactive 3 44 Guide to Informix Enterprise Replication Defining a Replication Server on japan Defining a Replication Server on japan This update anywhere replicate should include changes made on the Japan dalapan server Select g japan from the Server list box see Figure 3 9 on 4 ERM asks if you want to start Enterprise Replication on g japan Click Yes On the wizard page in Figure 3 29 select Root Server in the Server Type dialog box and g_usa in the Sync Server dialog box Click OK Figure 3 29 Add japan as a Replication Server Declare Server oorsee gt Replication Examples 3 45 Adding a Participant to reol4 Adding a Participant to repl4 To add japan as a participant to repl4 select repl4 and then choose Replicate gt Add Participant s You can select repl4 on the replicate display
301. t stop suspend or resume all the replicates Increased Performance You can significantly increase your replication performance when you use replicate groups Replicate groups can use parallelism to apply replicated transactions at target sites In a replicate group m each replicate must replicate to the same set of database servers m each replicate in the replicate group must be in the same Enterprise Replication state For more information see Changing Replicate States on page 8 14 The default replication process for a replicate group is sequential processing Nonsequential processing or parallel processing has the following two important restrictions m The data domains between groups must be disjoint That is a change to the data in one group must not affect the data in another group m Time dependencies between the replicates must not exist That is the order in which operations are performed on participants in the group must not affect the result Warning If time dependencies exist or domains are not disjoint and you select non sequential processing you can affect data consistency and integrity Before you define replicate groups consider the following factors m Replicate groups have separate group processing queues that process in parallel with all other replicate group queues If a trans action involves replicates that are not part of a replicate group the replicates are processed in a single sequen
302. t Option server_ group p 11 8 Element Purpose Restrictions repl_group Name of replicate group to start The group must exist Identifiers p 8 8 server_group Name s of server group s on The server s must be defined for Database Server which to start the group Enterprise Replication Group p 11 12 Usage The replicates defined in the replicate group repl_group enter the active state capture send on the database servers in server_group If no server group is specified all database servers in the replication system enter active state Example Connect to the default database server and start the replicate group accounts on the server groups g_hill and g_lake cdr start group accounts g_hill g_lake 11 66 Guide to Informix Enterprise Replication cdr start replicate cdr start replicate cdr start replicate The cdr start replicate command starts the capture and transmittal of repli cation transactions Syntax repl_name Connect Option server_ group p 11 8 Element Purpose Restrictions repl_name Name of the replicate to start The replicate must exist Identifiers p 8 8 server_group Name of server group s on The server group s must be Database Server which to start the replicate defined for Enterprise Group p 11 12 Replication Usage The cdr start replicate command causes the replicate rep _name to start on the server s target server If no target server is specified the repl_nam
303. t exit from ERM choose Cancel create the dbspaces and then return to ERM m Spooling Make sure that the spooling directory exists If the directory does not exist the declare server process fails Understanding Server Terminology Many of the pages in ERM ask you to select a server In ERM server is usually synonymous with database server group Each database server that participates in a replication system must be a member of a database server group For more information refer to Database Server Groups on page 11 12 Using Modes ERM has two modes expert mode and nonexpert mode Nonexpert mode is simpler to use because it has limited options This chapter documents both expert and nonexpert modes For information about the modes refer to Expert Mode on page 8 34 and Nonexpert Mode on page 8 33 Enterprise Replication Menus 8 7 Choosing Ellipses Choosing Ellipses A menu item that contains an ellipsis for example Define Replicate indicates that a wizard dialog box or a property sheet follows to help you complete a task The ERM wizards are described in Chapter 9 Enterprise Replication Manager Wizards Viewing Long Identifiers Identifiers are the names of objects that Dynamic Server and Enterprise Repli cation use such as database servers databases columns replicates replicate groups and so on An identifier is a character string that must start with a letter or an under s
304. t for others a With ERM activate ATS spooling on the replicate options page see Replication Options on page 3 39 a With the APIs set the ats_dir attribute in cdr_define_repl a With the CLU include the ats option with cdr define replicate 10 4 Guide to Informix Enterprise Replication Preparing to Use ATS Naming ATS Spool Files When ATS is active each aborted transaction is written to a file in the directory specified in the server definition The following table provides the naming convention for ATS spool files ats target source threadId timestamp sequence Name Description target The name of the database server receiving this replicate transaction source The name of the database server that originated the transaction threadId The identifier of the thread that processed this transaction timestamp The value of the internal time stamp at the time that this ATS instance was started sequence A unique integer This integer is incremented by ATS each time a transaction is spooled The naming convention ensures that all filenames that ATS generates are unique and therefore name collision is unlikely However when ATS opens a file for writing any previous file contents will be overwritten ATS does not append to a spool file if a name collision does occur with an existing file its original contents will be lost Diagnosing Enterprise Replication 10 5 Preparing to Use ATS Label Name TXH
305. t is to distribute replication data immediately Specifies that replicated data should be applied on the target as the owner of the table Permission checking for triggers should use the owner of the table instead of user informix 2 of 2 If the R_PARTICIPANTS flag bit is set in mflags the system expects the participants argument to be present This argument specifies the replicate participants for the replicate Participant information is stored in the CDR_plist structure The selectstmt member of that structure specifies the criteria for replication The following requirements are necessary for the statement m The SELECT clause can reference only columns from the table being replicated m The SELECT clause must contain at least the primary key m The SELECT clause can contain only limited user defined types For information about using user defined data types refer to Repli cating User Defined Data Types on page 5 15 m The WHERE clause of the SELECT statement cannot contain aggregates or constants 12 16 Guide to Informix Enterprise Replication cdr_define_repl Attribute Values for CDR_conf The CDR_repl_attrs includes the CDR_conf structure The arguments of the CDR_conf structure specify the conflict resolution method as follows Type of Value Value of flags Field Description Resolution type R_IGNORE Updates are applied as received no update collisions are detected or processed Replicates us
306. tabase server from the replication environment before the queues are properly emptied all data that has not been delivered for the database server might also be deleted To remove a database server from Enterprise Replication select the server and then choose Server gt Remove Server ERM asks you to confirm that you want to remove the database server If you confirm that you want to delete the replication server ERM removes all information about the database server from all Enterprise Replication catalogs This process can take a few minutes After completing the deletion ERM asks you to connect to another database server Removing a replication server is a two phase project First you must remove the links to all other replication servers and then you must remove the infor mation about the replication server itself To remove a replication server 1 Remove links to other replication servers a Inthe server list box choose a server for example g_usa that is not the one you want to remove b From the server display select the server to remove for example g_miami c Choose Server gt Remove Server 2 Remove the replication server a Inthe server list box choose the server that you want to remove g_miami b From the server display select the server to remove for example g_miami c Choose Server gt Remove Server To remove a server using CLU refer to cdr delete server on page 11 4
307. tate no capture no send on the database servers in the server_group list If the server_group list is omitted the replicate group repl_group enters the inactive state for all database servers partici pating in the replicate group Example The following example connects to the database server paris and stops the group accounts on server groups g_utah and g_iowa cdr stop group connect paris accounts g_utah g_iowa 11 70 Guide to Informix Enterprise Replication cdr stop replicate car stop replicate cdr stop replicate The cdr stop replicate command stops the capture and transmittal of trans actions for replication Syntax repl_name Connect Option server_ group p 11 8 Element Purpose Restrictions repl_name Name of the new replicate The replicate must be active and Identifiers p 8 8 not in a replicate group server_group List of server groups on which to The server group s must be Database Server stop the replicate defined for Enterprise Group p 11 12 Replication Usage The cdr stop replicate command causes the replicate repl_name to enter the inactive state no capture no send on the replicate servers in the server_group list That is the participants that are on the specified replicate servers are no longer active If the server_group list is omitted the replicate enters the inactive state on all database servers participating in the replicate If the replicate rep _name is containe
308. ted tables Replication frequency The ATS and RIS spooling files contain information about failed transactions You can use this information to help you diagnose problems that arise during replications For more information about these files refer to Chapter 10 Diagnosing Enterprise Replication The canonical message format sends floating point values in a machine independent format when you replicate data between dissimilar hardware platforms For information about database triggers refer to Using Cascading Deletes and Triggers on page 7 20 For information about replication frequency refer to Frequency Options on page 11 14 Enterprise Replication Features 2 9 Replicate Replicate State When you define a replicate the replicate does not begin until you explicitly change its state to active For more information refer to Changing Replicate States on page 8 14 Conflict Resolution Rules In update anywhere replication a conflict might arise because two users have updated the same table at the same time In that case Enterprise Repli cation uses the conflict resolution rules to decide which update has precedence You can specify any of the following conflict resolution rules Ignore Time stamp Stored procedure Time stamp plus stored procedure For more information refer to Choosing Conflict Resolution Rules and Scopes on page 7 13 Replicate Example Figure 2 5 on page 2 11 sho
309. teger column to the value assigned at the source database server Administering the Replication System Primary target replication systems are the easiest to administer because all updates are unidirectional and therefore no conflict detection or resolution rules are required Planning for Capacity All replication systems require you to plan for capacity changes For more information see Chapter 5 Setting Up Your Replication Environment Planning for High Availability In the primary target replication system if a target database server goes down or the network goes down Enterprise Replication continues to log information for the database server until it becomes available If a database server is unavailable for some time you might want to remove the database server from the replication system If the unavailable database server is the read write database server you will need to plan a course of action to change read write capabilities on another database server If you require a fail safe replication system you should select an update anywhere replication system 4 8 Guide to Informix Enterprise Replication Update Anywhere Replication System Update Anywhere Replication System An update anywhere replication system allows peer to peer update capabil ities This capability allows users to function autonomously even when other systems or networks in the replication system are not available Figure 4 5 Update
310. tem RRH Row 3 Group Id 24707080 Replicate Id 24707080 Table stores cdr customer DbOp Update RRS 390 s1s4 833437582 96 05 29 23 26 22 RRD 18 Larraine Hustin 2021 South Blvd A 8 399 2423745 0 00 0 00 0 00 0 00 83429 00 Untouched This Customer belongs to the Nation of Kamas RRH Row 4 Group Id 24707077 Replicate Id 24707077 Table stores cdr item DbOp Update RRS 390 s1s4 833437583 96 05 29 23 26 23 RRD 9 Keyboard173 A ALR Datsun Kboard 173 978 00 1399 00 866 00 23 00 1 8 00 12 00 Slow Moving Moderate Value Item Diagnosing Enterprise Replication 10 7 BYTE and TEXT Information in ATS Files BYTE and TEXT Information in ATS Files When the information recorded in the ATS file includes BYTE or TEXT data the replicated row data RRD information is reported as the following examples show Example 1 lt 1200 TEXT PB 877 necromsv 840338515 96 08 17 20 21 55 gt where m 1200 is the size of the data m TEXT is the data type it is either BYTE or TEXT m PB is the storage type PB when the BYTE or TEXT is stored in the tablespace BB for blobspace storage m The next two fields are the server identifier and the time stamp for the column if the conflict resolution rule is defined for this replicate and the column is stored in a tablespace Example 2 lt 500 NoChange TEXT PB 877 necromsv 840338478 96 08 17 20 21 18 gt where NoChange after the 500 indicates that the TEXT data has a size
311. the integer value in the for this replicate spooling file s INTEGER The columns of the row to be applied to the This list of column values is not parsed if the replicate target table replicate action type in regular action type that the procedure returns is S 0 or X SQL format You can use the arguments to develop application specific procedures For example you can create a procedure in which a database server always wins a conflict regardless of the time stamp For an example see A Stored Procedure Example on page D 3 The following list includes some items to consider when you use a procedure for conflict resolution m Determining when the procedure executes Optimized mode invokes the procedure if a collision is detected and the replicate source database server is either different from the server shadow column in the target row or if the source update time is less than or equal to the target row If you do not choose to optimize the execution of your procedures a procedure executes every time Enterprise Replication detects a collision m Any action that a procedure takes as a result of replication does not replicate m Frequent use of procedures might affect performance Tip Do not assign a procedure that is not optimized as a primary conflict resolution rule for applications that predominantly insert rows successfully Enterprise Replication Processes 7 19 Using Cascading Deletes and Triggers Ignor
312. their defaults If you want to view the completed wizard page see Figure 3 6 on page 3 22 Click OK Displaying the Hierarchy After ERM defines the miami leaf server the display returns to the main ERM display Click the database server icon to show a list of replication servers The display changes depending on which server you select from the Server list box Try selecting g_italy g denver and g_ miami to see how the display changes None of the lists indicates the hierarchy of the servers 3 50 Guide to Informix Enterprise Replication Viewing the Server Properties To see the replication hierarchy select Server gt Hierarchical Routing The Hierarchical Routing view in Figure 3 34 shows that boston and denver are children of the usa root server and that miami is a child of the boston nonroot server Figure 3 34 Hierarchical Routing El Replicanon System View I Hierarchical Routing View al 3 g_boston DE SS KA g_miami E g_denver Viewing the Server Properties You can also see parent child relationships when you look at server properties Select the miami server from either the Hierarchical Routing View window or from the main ERM display Then select Server gt Server Properties Select the Routing tab in the Server Properties window The display shows that miami is a leaf and its parent is boston as in Figure 3 35 Figure 3 35 Server Properties General a Spooing Directories na Dialog Box Server Proper
313. tial queue m Replicate group names are global within the replication system Each replicate group name must be unique Do not define a replicate group and a replicate with the same name Enterprise Replication Features 2 13 Catalog Catalog Each database server that participates in Enterprise Replication has a catalog in the syscdr database that contains information about the replication system For all root and nonroot replication servers this catalog is a global catalog that maintains a global inventory of replication system options states and statistical data The global catalog contains replicate definitions Enterprise Replication server definitions m m m Enterprise Replication object states m participant definitions m replicate group definitions The tables in one global catalog are replicated to the global catalogs of all other replication servers thus you can manage the entire replication environment from one replication server For information about managing replication servers and their global catalogs refer to Chapter 11 Command Line Utility and Chapter 8 Enterprise Replication Menus Leaf database servers have a limited catalog Because the parent database server always manages operations that involve a leaf database server the catalog of the leaf database server can contain only enough data to allow it to interact with its parent server Limiting the catalog of leaf database servers
314. ties Replication Examples 3 51 Preparing for Enterprise Replication Chapter 4 Selecting Enterprise Replication Systems Chapter 5 Setting Up Your Replication Environment Chapter 6 Preparing Data for Replication Selecting Enterprise Replication Systems In This Chapter Primary Target Replication age Data Dissemination Data Consolidation Workload Partitions Workflow Replication Factors in Primary Target Systems i Selecting Data for Primary Target Replication A Administering the Replication System Planning for Capacity Planning for High Availability Update Anywhere Replication Ga Facts to Consider Selecting Data for Replication Administering the Replication System Delivering Consistent Information Planning for Capacity Planning for High Availability 4 3 4 3 4 4 4 5 4 6 4 7 4 7 4 8 4 8 4 8 4 8 4 9 4 9 4 10 4 10 4 10 4 10 4 2 Guide to Informix Enterprise Replication In This Chapter This chapter describes Enterprise Replication system types and discusses the trade offs associated with performance and data availability Enterprise Replication supports the following replication types m Primary target m Update anywhere Primary Target Replication System In the primary target replication system the flow of information is in one direction That is the primary always sends data to the target The target does not send data to the primary In thi
315. tion Creating an Update Anywhere Replicate Participants Identical The wizard page in Figure 3 25 asks if the participant definitions that is the database name owner and table name are identical Click the Yes option button and then click Next Figure 3 25 Identical Replicate Definitions Selecting a Table The wizard pages for selecting a table and columns for update anywhere replication are the same as the corresponding wizard pages for primary target replication Replication Examples 3 41 Creating an Update Anywhere Replicate The wizard page in 0 lets you select the table to replicate Enter the name sof the database the table owner the login name you used when you created the table and the name of the table for this replicate state Click Next Selecting the Columns The wizard page in Figur 5 lets you specify which columns of the table should be replicated The SELECT statement causes all columns of the table to be replicated There is no WHERE clause so all changes to state table will be replicated Click Finish Figure 3 26 Prepare Select Statement 3 42 Guide to Informix Enterprise Replication Creating an Update Anywhere Replicate Summary The Replicate Summary page in Figure 3 27 lets you review the attributes of the replicate before ERM actually creates the replicate Read the summary to verify that it shows the choices that you made Use the scroll bar to see the re
316. tion Evaluates Images in a Complex Transaction Transaction Header Log Update 72 Type Insert Table A Row 100 Log Update 75 Type UpBef Table B Row 225 Log Update 76 Type UpAft Table B Row 225 Log Update 78 Type UpBef Table A Row 100 Log Update 79 Type UpAft Table A Row 100 Log Update 85 Type UpBef Table B Row 225 Log Update 86 Type UpAft Table B Row 225 Log Update 88 Type UpBef Table A Row 100 Log Update 89 Type UpAft Table A Row 100 Repl ID 1 Repl ID 3 Repl ID 2 Repl ID 4 D 2 Guide to Informix Enterprise Replication Compress Transaction Transaction Header Log Update 89 Type Insert Table A Row 100 Log Update 75 Type Delete Table B Row 225 Log Update 86 Type Insert Table B Row 225 Primary Key Changed A Stored Procedure Example A Stored Procedure Example This example illustrates the function of conflict resolution by stored procedure The stored procedure will resolve a conflict for rows in a table defined as CREATE TABLE employees emp_num int empname CHAR 15 salary INT PRIMARY KEY emp_num WITH CRCOLS LOCK MODE ROW The replicate is defined as SELECT FROM employees The emp_numis the primary key The primary key is passed with the other replicated row data and the local target row data Fine Tuning Enterprise Replication D 3 A Stored
317. tion and the options that you use determine the replication topology Enterprise Replication provides three replication topologies m Fully connected m Hierarchical tree m Forest of trees For information on how to define replication servers see cdr define server on page 11 33 and Preparing to Use the Replication Manager on page 8 6 Enterprise Replication Features 2 3 Topology Terminology topology Term Topology Terminology Enterprise Replication uses the terms in the Figure 2 1 to describe replication Figure 2 1 Replication Topology Terms Definition Root server Nonroot server Tree Parent Child Leaf server environment 2 4 Guide to Informix Enterprise Replication An Enterprise Replication server that is the uppermost level ina hierarchically organized set of information The root is the point from which database servers branch into a logical sequence All root database servers within Enterprise Replication must be fully interconnected An Enterprise Replication server that is not a root database server but that has a complete global catalog and is connected to its parent and to its children A data structure that contains database server s that are linked in a hierarchical manner The topmost node is called the root The root can have zero or more child database servers the root is the parent database server to its children A relationship between database servers in a tree
318. tion chosen for the replicate m Conflict resolution scope m Conflict resolution rule m Stored procedure For more information refer to Choosing Conflict Resolution Rules and Scopes on page 7 13 To find this information using the CLU refer to cdr list replicate on page 11 48 8 18 Guide to Informix Enterprise Replication Viewing Replicate Properties Spooling Tab The Spooling tab shows whether ATS and or RIS spooling are active For information about spooling refer to Chapter 10 Diagnosing Enterprise Replication To find this information using the CLU refer to cdr list replicate on page 11 48 Frequency Tab Click the Frequency tab in the Replicate Properties window to view or change the frequency and then click Apply For more information refer to Frequency Options on page 11 14 Important Enterprise Replication calculates a new replication schedule at the time you select Apply For example if you change the time based frequency value from every hour to every two hours and select Apply at 12 20 P M replication occurs at 2 20 P M Participant Properties The Participant Properties window shows the columns and the WHERE clause selected for the participant To view participant properties select a participant and then choose Replicate gt Participant Properties ERM displays the properties of the participant as Figure 8 7 shows Figure 8 7 Participant Properties Window
319. tional information about various options You can perform all the operations that are described in this chapter with the command line utility CLU described in Chapter 11 or with application programming interface API calls described in Chapter 12 All wizards include command buttons at the bottom of a window to allow you to navigate through the wizard The Replication Manager uses the following command buttons Command lt Back Next gt Cancel Create Finish Help Action Returns to the previous page Moves to the next page in sequence keeping changes from previous pages Discards any changes and terminates the process Create an object that matches the description Completes the task Requests help Enterprise Replication Manager Wizards 9 3 Defining a Replicate Defining a Replicate To define a replicate choose Replicate gt Define Replicate The Define Replicate menu item accesses the Define Replicate wizard The wizard provides a series of windows that guide you through the process of defining a replicate The Define Replicate wizard first lists the steps required to define a replicate and then asks you to choose a name for the replicate Defining a Replicate Name If you are in expert mode the wizard asks for a replicate name and replicate type as Figure 9 1 shows If you are in nonexpert mode the wizard does not ask for the replicate type because only primary target replication is available in
320. top_cdr is executed If the evaluation process is running and the logical log ID for the replay position no longer exists when Enterprise Replication is started then the restart partially fails the database server log contains an error message stating that the replay position is invalid If the restart partially fails no database updates performed on the local database server are replicated Warning Informix recommends that you issue cdr_start_cdr and cdr_stop_cdr with extreme caution Use these functions during a period of little or no database activity and keep the Enterprise Replication downtime to a minimum Transactions that occur during this period are not replicated hence tables can become unsynchronized 12 38 Guide to Informix Enterprise Replication cdr_start_group cdr_start_group The cdr_start_group function starts the capture and transmittal of repli cation transactions for replicates contained in a replicate group Syntax include cdrapi h int cdr_start_group group servers time which char group CDR_idlist servers time_t time void which group is the replicate group name servers is an optional list of database server groups for which replication should begin time is not used but cannot be omitted Use time_t 0 for that argument which if the call fails this pointer references information about the error See Using the Stored Error Information on page C 1 Usage T
321. toring Replication Tvent The Replicate Menu Managing Replicates and Participants Changing Replicate States Changing the Primary Participant Viewing Replicate Properties Group Menu i Defining a Replicate Group Modifying Groups ae Changing the State of a Group Viewing Replicate Group Properties Server Menu Suspending and Resuming a Database Sawer Finding or Changing the Server State Viewing the Replication Hierarchy Changing to Primary Changing to Target Starting and Stopping tebie Replication Specifying Privileges Removing a Database Server from Entemriso Replication Reloading the Global Catalog Viewing Database Server Properties View Menu 3 By Replicate and By Server Toolbar and Status Bar Guide to Informix Enterprise Replication Chapter 9 Window Menu Nonexpert Mode Expert Mode List of Open Windows The Help Menu Help Topics Using Help Contacting Informix About Replication Manager Hierarchical View Menus Replication Scripting View Menus Enterprise Replication Manager Wizards In This Chapter Defining a Replicate Defining a Replicate Name Choosing a Conflict Resolution Procedure Choosing Replicate Options Selecting the Replication Frequency Selecting Servers to Participate in the Replicate Specifying Identical or Non Identical Participants Defining Participant Attributes Choosing the Columns to Replicate Reviewing Replicate Sum
322. transactions if a replicate group is suspended For example a transaction that updates tables X and Y will be split if replication for table X is suspended gt gt Command Line Utility 11 73 cdr suspend group Example The following example connects to the default database server INFORMIXSERVER and suspends the replicate group accounts cdr suspend group accounts 11 74 Guide to Informix Enterprise Replication cdr suspend replicate cdr suspend replicate The cdr suspend replicate command suspends delivery of replication data Syntax cdr suspend replicate repl_name p 11 8 gt gt Usage The cdr suspend replicate command causes the replicate repl_name to enter the suspend state capture no send for all participants If the replicate repl_name is contained in a replicate group this command fails When repl_name is in a replicate group use the cdr suspend group command on page 11 73 You cannot add a replicate that is suspended to a replicate group even if the replicate group is also suspended Warning When a replicate is suspended Enterprise Replication holds the replication data in the send queue until the replicate is resumed If lots of data is generated for this replicate while it is suspended the send queue space can fill causing data to be lost Warning Enterprise Replication does not synchronize transactions if a replicate is suspended For example a transaction
323. ts smart large objects and user defined data types For general information on data types refer to the Informix Guide to SQL Reference and Informix Guide to Database Design and Implementation Replicating on Heterogeneous Hardware Enterprise Replication supports all primitive data types across heteroge neous hardware If you define a replicate that includes non primitive data types for example BYTE and TEXT data then the application must resolve data representation issues that are architecture dependent If you use floating point data types with heterogeneous hardware you might need to use canonical format for the data transfers Canonical message format sends floating point values in a machine independent format Replicating Simple Large Objects BYTE and TEXT data types are simple large objects These data types can be stored in the tablespace with the rest of the table columns or in blobspaces Replicating from Tablespaces or Blobspaces BYTE and TEXT data that is stored in tablespaces rather than in a blobspace is placed in the logical log Enterprise Replication reads the logical log to capture and evaluate BYTE and TEXT data for potential replication Setting Up Your Replication Environment 5 11 Replicating Simple Large Objects BYTE and TEXT data that is stored in blobspaces is not placed in the logical log Enterprise Replication retrieves BYTE and TEXT data from blobspaces before sending the data to the target databas
324. ueue is composed of the following three pieces An initial part syscdr that indicates that the table describes Enter prise Replication m An abbreviation that indicates which queue the table describes m A suffix either _buf or _txnthat specifies whether the table includes buffers or transactions Columns of the Transaction Tables Selecting from these tables provides information about the contents of each queue For example the following SELECT statement returns a list of all trans actions queued on the send queue SELECT FROM syscdrsend_txn The following example returns a list of all transactions queued on the in memory send queue and returns the number of buffers and the size of each buffer for each transaction on the send queue SELECT cbkeyserverid cbkeyid cbkeypos count sum cbsize from syscdrsend_buf group by cbkeyserverid cbkeyid cbkeypos order by cbkeyserverid cbkeyid cbkeypos All queues are present on all the replication servers regardless of whether the replication server is a source or a target for a particular transaction Some of the queues are always empty For instance the send queue on a target only server is always empty Each queue is two dimensional Every queue has a list of transactions headers Each transaction header in turn has a list of buffers that belong to that transaction Columns of the Transaction Tables All the tables whose names end with _txn have the same columns and the sa
325. unction adds the participants in the partici pants list to the replicate The replication state is initialized to inactive If the value of op is ALREMOVE the function removes the participants in the participants list from the replicate The selectstmt member of the CDR_plist structure is not required and is ignored if it is present For the definition of the CDR_plist structure refer to API Structures on page 12 5 12 32 Guide to Informix Enterprise Replication cdr_prune_errors cdr_prune_errors The cdr_prune_errors function prunes errors from the severe error table based on time or time range Syntax include cdrapi h include datetime h include decimal h int cdr_prune_errors uppertime lowertime reviewed_only dtime_t uppertime dtime_t lowertime int reviewed_only uppertime is the upper most recent time limit for deletion of errors This value must be specified lowertime is the lower earliest time limit for deletion of errors If a null is passed all errors earlier than uppertime are deleted reviewed_only is a flag that specifies which errors to delete Usage The cdr_prune_errors function deletes errors from the severe error table on all database servers involved in replication for a time range or for all errors before a specified time If lowertime is null the function deletes all errors that occurred at or before uppertime If both time values are specified then e
326. ure Data BP aot og 9 5 Choosing Replicate Options n 9 6 Selecting the Replication Frequency 2 9 7 Selecting Servers to Participate in the Replicate 9 9 Specifying Identical or Non Identical Participants 9 10 Defining Participant Attributes 9 12 Choosing the Columns to Replicate 2 913 Reviewing Replicate Summary 914 Adding a Participant ee eee ee 9 15 Defining a Replicate Group 0 ee 915 Choosing a Group Name pai a a OA Choosing the Replication Interval fon ie Group AOR GS ob Bee GALO Selecting Replicates for the Replicate Group 917 Generic Configuration Wizard 2 2 2 wee 917 Choosing a Naming Scheme Rae ch va ah ue oh ok da 20518 Naming Update Anywhere Roslin A A tie hk ty A gs Ja 7951S Naming Primary Target a a He tas ty hg Ay sr ELD Describing the Replicates fos hs 2s te aaa ae ce hy gt 99220 Describing the Participants 2 2 1 we 9 21 Customizing the Generic Replicates 2 9 23 9 2 Guide to Informix Enterprise Replication WIN NT In This Chapter This chapter documents the ERM wizards and guides you through some basic tasks The previous chapter Chapter 8 Enterprise Replication Menus covers the ERM menu options The on line help provides addi
327. utility Intro 14 finderr utility Intro 14 Floating point numbers canonical format 11 30 12 16 Frequency attributes description 11 14 in list of replicates 11 48 of a replicate 11 58 12 16 12 25 of a replicate group 12 11 12 12 12 24 structure members 12 6 G Global Language Support GLS locale Intro 5 locale of date 11 15 Group See Replicate group Database server groups H Help context sensitive 8 37 menu 8 35 Hierarchical view print schematic 8 38 save report 8 38 High availability data replication support of 5 3 Homogeneous platforms 5 15 Icons feature Intro 9 Important Intro 9 platform Intro 9 product Intro 9 Tip Intro 9 Warning Intro 9 Identifiers 8 8 Ignore conflict resolution rule 7 20 Important paragraphs icon for Intro 9 Inactive state definition of 8 16 8 22 Industry standards compliance with Intro 16 INFORMIXDIR bin directory Intro 5 INFORMIXSQLHOSTS environment variable E 2 ISO 8859 1 code set Intro 5 L List Enterprise Replication servers 11 50 replicate groups 11 47 replicates 11 48 Locale default Intro 5 en_us 8859 1 Intro 5 Locales preparing 5 16 Log based data capture 1 8 Logging unbuffered 5 10 Logical log capacity planning 5 5 reading of 7 3 7 5 Long identifiers 8 8 M Machine notes Intro 15 Machine independent format 11 30 12 16 Menus Help 8 35 Replicate 9 4 Replicate group 8 20 Server 8 25 View 8 32 Window 8 33 Message file for er
328. v function registers a database server as a replication server Syntax include cdrapi h int cdr_define_serv server attrs char server CDR_serv_attrs attrs server is the name of a database server group attrs are the database server attributes Usage The cdr_define_serv function registers the database server specified by the database server group server as a replication server with the attributes attrs A replication server is simply a database server that includes replication infor mation A database server cannot participate in Enterprise Replication until it has been registered as a replication server The cdr_define_serv function stores information about the replication server in the global catalog in the syscdr database If the syscdr database does not already exist the cdr_define_serv function creates it Tip Do not try to examine the syscdr database The information is stored ina format that is suitable only for use by the database server For information about replication servers examine the syscdrservers table in the sysmaster database For a description of the Enterprise Replication tables in the sysmaster database refer to Appendix B SMI Tables for Enterprise Replication The database server group must be defined in the sqlhosts file UNIX or the SQLHOSTS registry key Windows NT For more information refer to Database Server Groups on page 12 3 12 18 Guide to Informix Enterprise R
329. valid replicate can be defined as part of a replicate group However each replicate in the replicate group must meet the following restrictions m All the replicates must be defined over the same set of database servers m All the replicates must be in the same replication state For information about replication states refer to Changing Replicate States on page 8 14 m A replicate can be in only one group at a time Once a replicate is defined as part of a replicate group control and configu ration is only allowed with replicate group control commands You cannot control a replicate individually until either the replicate is removed from the replicate group or the replicate group is deleted For a discussion of parallel versus sequential processing refer to Replicate Group on page 2 12 Example The following example connects to the default server and defines the replicate group accounts with replicate participants repl1 repl2 and repl3 cdr define group accounts repll repl2 repl3 11 26 Guide to Informix Enterprise Replication Connect Option Element Syntax Conflict Options cdr define replicate p 11 28 p 11 8 Purpose cdr define replicate cdr define replicate The cdr define replicate command defines a replicate in the global catalog replicate participant modifier Frequency Options Special Options p 11 14 p 11 30 Restrictions Syntax modifier
330. ver dbserver as the origin for all control and configuration calls A connection is established to the database server dbserver If dbserver is null or if you do not invoke this call before making other API calls the connection defaults to the database server that the INFORMIXSERVER environment variable specifies The database server specified must be defined in the global catalog To define the database server for Enterprise Replication use cdr_define_serv Unlike the other API commands that Enterprise Replication uses the cdr_connect function uses the database server name All other API commands that reference a database server use the name of the database server group For more information about database servers and database server group names refer to Database Server Groups on page 12 3 12 10 Guide to Informix Enterprise Replication cdr_define_group cdr_define_group The cdr_define_group function creates a replicate group in the global catalog Syntax include cdrapi h int cdr_define_group group attrs repls freq which char group uint4 attrs CDR_idlist repls CDR_freq freq void which group is the name of the replicate group attrs are the group attributes repls is the list of replicate names freq are the frequency attributes which if the call fails this pointer references the argument that caused the error see Appendix C Usage The cdr_define_group function de
331. w on the target database server with the last most recent update The time stamp Trep represents the time stamp on the incoming row Enterprise Replication first checks to see if a row with the same primary key exists in either the target table or its corresponding delete table Enterprise Replication Processes 7 15 Time Stamp Conflict Resolution Rule If the row exists Enterprise Replication uses the latest time stamp to resolve the conflict Figure 7 11 Conflict Resolution Based on the Time Stamp Database Operation Row Exists on Target Time Stamp Insert Update Delete No n a Apply row Apply row Apply row Convert UPDATE to INSERT into Enterprise INSERT Replication delete table Yes Tlast update lt Apply row Apply row Apply row Trepl Convert INSERT to UPDATE Tlast_update gt Discard row Trepi UNIX WIN NT iE Tlast_update z Trep Apply row if no procedure is defined as a secondary conflict resolution rule Otherwise invoke the procedure Important Do not remove the delete tables created by Enterprise Replication The delete table is automatically removed when the last replicate defined with conflict resolution is deleted The time stamp conflict resolution rule assumes time synchronization between cooperating Enterprise Replication servers All time stamps and internal computations are performed in Greenwich mean t
332. witch between windows select an item from the list When ERM is first installed it is always in nonexpert mode Nonexpert mode has the following characteristics m Primary target replication is the only replication type m All replication servers must be fully connected m ERM assumes that all servers are on Windows NT Enterprise Replication Menus 8 33 Expert Mode In primary to secondary or primary target replication one database server is the primary replication server All changes to the primary or source database server are replicated to the secondary or target database servers Changes to the secondary database servers are not replicated to the primary database server Ina fully connected topology all replication servers are connected to all other replication servers That is all replication servers are root servers Nonexpert mode does not allow for a hierarchical or tree topology Nonexpert mode assumes that all of your database servers are on Windows NT systems If you have UNIX database servers you must be careful to change the default pathnames to UNIX pathnames Expert Mode Expert mode increases the number of options that the Replication Manager menu offers and lets you choose additional types of replications Expert mode has the following features that are not available in nonexpert mode Update anywhere replication Secondary to primary replication Hierarchical routing Scripting Generic configu
333. ws the replicate Kiwi A replicate defines the name and type of the replicate conflict resolution rule and options Each participant within the replicate identifies the data to replicate from one database server to another In Figure 2 5 the inventory database on both database servers NewZealand and Australia includes the table products which might be defined as follows CREATE TABLE products product CHAR 20 prod_id INTEGER perish CHAR 1 y perishable n not perishable unit_cost DECIMAL 2 10 Guide to Informix Enterprise Replication Replicate Perishable items for example produce that has a short shelf life are listed only in the local database Inserts or updates on perishable items should not be replicated to other database servers Figure 2 5 Replicate Kiwi T7 Replicate name Kiwi Replicate Kiwi Options Replication type Update anywhere Aborted transaction spooling on Conflict resolution rule Time stamp Row information spooling on Triggers on replicated tables active Canonical message format off Replication frequency time based NewZealand Australia qi Participant Participant Database inventory Database inventory Server NewZealand Server Australia Owner smith Owner smith Teble products Teble products SELECT FROM products SELECT FROM products where perish n where perish n and location Aus
334. x Enterprise Replication cdr delete replicate cdr delete replicate The cdr delete replicate command deletes a replicate from the global catalog Syntax cdr delete replicate repl_name J Connect Option p Usage The cdr delete replicate command deletes the replicate repl_name from the global catalog All replication data for the replicate is purged from the send queue at all participating database servers If repl_name is contained in a replicate group this command fails You must remove the replicate from the replicate group before you can delete it To add or delete a participant using ERM refer to Deleting a Replicate on page 8 13 Example The following command connects to the default database server INFORMIXSERVER and deletes the replicate smile cdr del rep smile Command Line Utility 11 39 cdr delete server cdr delete server The cdr delete server command deletes a database server from the global catalog Syntax cdr delete server server_ group p 11 8 Element Purpose Restrictions Syntax server_group Name of server group to remove The server group must be Database Server from the global catalog currently defined in Enterprise Group p 11 12 Replication Usage The cdr delete server command deletes the database server in server_group from the global catalog removes the database server from all participating replicates and purges all replication data
335. xt line Line 5 names the replicate repl1 and specifies that conflicts should be ignored Line 6 describes one participant in the replicate The P indicates that in this replicate usa is a primary server That is if any data in the selected columns changes that changed data should be sent to the secondary server s Line 7 describes a second participant in the replicate The R indicates that in this replicate italy is a secondary server The specified table and columns receive information that is sent from the primary server Changes to those columns on italy are not replicated Replication Examples 3 7 Cause a Replication Line 8 This line displays the replicate that you defined so that you can verify that the definition succeeded The command returns the following information REPLICATE STATE CONFLICT FREQUENCY OPTIONS repll INACTIVE ignore immediate row Line 9 The display for line 8 shows that the STATE of the replicate is INACTIVE Lines 5 through 7 describe a replicate but do not make the replicate active Line 9 makes the replicate active If any changes are made to the manufact table the changes will be replicated to the other participants in the replicate Line 10 Line 10 displays the replicate so that you can verify that the STATE has changed to ACTIVE The command returns the following information REPLICATE STATE CONFLICT FREQUENCY OPTIONS repll ACTIVE ignore immediate row Cause a Replication Now you can m
336. y database server are replicated to the other participants in the replicate To specify a different participant as the primary database server in a replicate select the participant that should become the primary database server and choose Replicate gt Change to Primary from the Replicate menu Viewing Replicate Properties The Replicate Properties window summarizes the properties you have assigned to a replicate To view replicate properties select a replicate and then choose Replicate gt Replicate Properties The Replicate Properties window has the following tabs General Conflict Resolution expert mode only Spooling expert mode only Frequency Enterprise Replication Menus 8 17 Viewing Replicate Properties General Properties Tab In nonexpert mode the General tab displays only the name of the replicate In expert mode the General tab displays the replicate name and indicates whether triggers and canonical message format are enabled as Figure 8 6 shows Figure 8 6 eS Group Properties Dialog Box in Nonexpert Mode and in Expert Mode For information about enabling triggers refer to Chapter 7 Enterprise Replication Processes For information about canonical message format refer to Replicate Options on page 2 9 Conflict Resolution Tab Ss Important This option is available only in expert mode The Conflict Resolution tab displays the following information about the conflict resolution informa
337. y group cdr modify replicate cdr modify server x Guide to Informix Enterprise Replication 10 3 10 3 10 4 10 8 10 9 10 11 10 14 11 3 11 5 11 6 11 6 11 7 11 8 11 8 11 9 11 11 11 12 11 13 11 14 11 16 11 19 11 20 11 22 11 24 11 25 11 27 11 33 11 38 11 39 11 40 11 43 11 44 11 47 11 48 11 50 11 53 11 55 11 59 Chapter 12 cdr resume group cdr resume replicate cdr resume server cdr start cdr start group cdr start replicate cdr stop cdr stop group cdr stop replicate cdr suspend group cdr suspend replicate cdr suspend server API Functions In This Chapter Basic Information for APIs Database Server Groups Time Specifications Identifiers API Structures Severe Error Table Enterprise Replication APIs cdr_connect cdr_define_group cdr_define_repl cdr_define_serv cdr_delete_group cdr_delete_repl cdr_delete_serv cdr_error_reviewed cdr_modify_group cdr_modify_repl cdr_modify_replmode cdr_modify_serv cdr_modify_servmode cdr_move_errortab cdr_participate_group cdr_participate_repl cdr_prune_errors cdr_prune_single_error cdr_resume_group cdr_resume_repl 11 61 11 62 11 63 11 64 11 66 11 67 11 68 11 70 11 71 11 73 11 75 11 77 12 3 12 3 12 3 12 5 12 5 12 5 12 7 12 8 12 10 12 11 12 14 12 18 12 20 12 21 12 22 12 23 12 24 12 25 12 27 12 28
338. ystem you defined As discussed in the previous paragraph defining replication on a table might cause your transactions to log more data Setting Up Your Replication Environment 5 5 Send and Receive Message Queues When the database server switches from one logical log to the next a processing burden is placed on Enterprise Replication Avoid logical log configurations that result in frequent switching from one logical log to the next One logical log switch per hour during normal processing is a good target Plan to have sufficient logical log space to contain 12 to 24 hours of normal log activity Send and Receive Message Queues The term message queue refers to both the send queue and the receive queue The send queue resides at the source database server and contains committed transaction information The receive queue resides at the target database server and contains information received by the target database server for application at the table level The send and receive queues are dbspaces To determine the size of your send queue determine your log usage and then consider how much data you can collect if your network goes down For example assume that you usually log 40 megabytes of data each day but only 10 percent of that is replicated data If your network is down for 24 hours and you estimate that you will log 4 megabytes of replicated data each day the dbspace you identify for the send queue must be at least 4 megabytes

Guide to Informix Enterprise Replication, Version 9.2

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