Activation of a dormant sibling computer in a communication
Contents
1. 1989 90 Quotron F X Trader Beta Version User Manual Spring 1990 Quotron F X Trader Beta Version System Admin istration Manual Spring 1990 Copies of the foregoing documents are included as part of the above cited application entitled Detection and Prevention of Duplicate Trading Transactions Over a Communications Network and are hereby incorpo rated by reference BACKGROUND ART A computer network comprises a plurality of nodes that are connected together to allow for the exchange of data between computers located at different nodes In most networks certain of the computers are particu larly critical and a serious degradation of functionality results if such a computer malfunctions or otherwise is inaccessible for an extended period of time Not only is communication with the faulty computer interrupted but any associated network functions performed by the computer remain unexecuted potentially causing con siderable havoc The magnitude of this problem can be reduced by providing two computers at each node for example a main and a backup computer Thus when the main computer breaks down the backup computer can take its place However implementing a system that can switch computers at the nodes can be difficult The difficulty arises from the fact that each computer con nected to the network must be identified by a unique 5 15 20 25 30 35 45 55 65 2 address and the network m2. use the principles of the present invention to address the computers We claim 1 In a communications network having a plurality of nodes each being identified by a respective active node address at least one of said nodes being a redundant node having at least two sibling computers sharing a common active node address for communicating over said communications network a method for identifying the sibling computers comprising the computer imple mented steps of assigning a unique respective dormant node address different from said common active node address to each sibling computer and attaching said each sibling computer to the communi cations network by using said unique respective dormant node address to connect said each sibling computer to the network determining whether said common active node address is already being used to connect any 15 20 25 30 35 45 50 55 65 8 other sibling computer to the communications network and if there is no other sibling computer already using said common active node address to connect to the communications network temporarily removing said each sibling com puter from the network assigning said common active node address to said each sibling computer and using said common active node address to re connect said each sibling computer to the net work 2 The method of claim 1 further comprising the computer implemented steps of removing from the commu
3. and then through the Tokyo city node C1 Upon receipt of the message at Bank Y it gets routed to the Zurich city node then to the Bank Y bank node B31 and finally to the trading terminal T311 The path that the message takes between the Tokyo C1 and Zurich C4 city nodes is entirely up to the decision making function of the network For example the message may go through New York C2 only or London C3 only or both New York and London before reaching Zurich There are a variety of messages and conimanibations which can occur between traders however the most fundamental is a communication regarding the negotia tion of the sale or purchase of currency Briefly in an exemplary system the trading conversation is initiated by one trader requesting a quote RFQ from another trader The other trader has a variety of options the first of which includes whether he will even answer the RFQ Other options include responding with a quote or sending written messages back to the requesting party The conversation is ended by either making a deal or refusing a deal and hanging up Referring now to FIG 2 an exemplary trading termi nal screen is shown having a plurality of panels An indicative rates panel 11 is provided and contains elec tronically updated indicative trading rates for selected currency pairs wherein a currency pair is the two types of currency which are to be involved in the potential transaction Example of currencies are the U
4. at the same time however both of them can be in dormant mode simultaneously These constraints are ensured by an appropriate start up process for each sibling computer When each computer is started up it first determines whether any other sibling computer in the node is iden tified by the common active node address If it is not then the sibling computer may assume its active mode by temporarily removing itself from the network changing its network address to equal the active node address and using that active node address to re con nect itself to the network BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will be apparent from the following description of a presently preferred embodiment taken in connection with the accompanying drawings in which FIG 1 is a system level schematic representation of a city network system having bank nodes connected thereto FIG 2 is a schematic diagram illustrating an exem plary display screen of the trading system having a plurality of windows disposed therein FIG 3 is a schematic diagram of an exemplary net work node having sibling computers FIG 4 is a flowchart illustrating in general an exem plary method used by a node administrator to swap sibling computers at a bank node and FIGS 5A and 5B are flowcharts illustrating the start up sequence of a sibling computer ensuring that only one computer at the node is active DETAILED DESCRIPT
5. ensure that only the first of the sibling computers on which the start up procedure is run on is assigned the active node address for the bank node Similarly when the administrator is attempting to swap sibling computers these steps ensure that the pre viously active sibling computer has indeed been placed in its dormant state The following step as shown in FIGS 5A and 5B is to extract the active node name from the signature file 42 Similarly to the addressing scheme the bank node has a single node name which is used by the sibling computers when in their active state Also each sibling computer has a unique node name associated to its oper ation in a dormant state It is then determined whether DECnet is up 43 If it is up then the following step is to get the executor address of the computer on which the start up proce dure is being run 44 The executor address is the address that the computer is currently identified by Thus it may be either the active node address or the computer s dormant address In the next step 46 if it determined that the executor address is the same as the active node address 47 then the start up process ends since the computer is already running in active status However if the executor address is different from the active node address 48 then the next step is to shut down DECnet 49 In an exemplary system shutting down DECnet may require several steps For example it may be necessary to wait unt
6. 64 187 5 121 486 6 1992 Kurihara et al 395 325 5 125 076 1 1992 Faber et al vee 395 200 5 167 035 11 1992 Mann et al 395 575 5 191 651 3 1993 Halim et al 395 200 5 198 805 3 1993 Whiteside et al 340 825 06 OTHER PUBLICATIONS Quotron Systems Inc Quotron F X Trader System Overview Winter 1989 90 Quotron Systems Inc Quotron F X Trader Beta Version User Manual Spring 1990 Quotron Systems Inc Quotron F X Trader Beta Version System Administration Manual Spring 1990 Quotron Systems Inc Interactive Demo Script with copies of display screens as shown in Lisbon Por tugal Spring Summer 1989 J G Sams Node Processor for Distributed System Control IBM Technical Disclosure Bulletin vol 23 No 5 Oct 1980 pp 1811 1812 Primary Examiner Parshotam S Lall Assistant Examiner Krisna Lim Attorney Agent or Firm Robbins Berliner amp Carson 57 ABSTRACT A respective unique dormant address is permanently associated with each of two sibling computers located at a particular node of a communications network A selected one of the sibling computers is activated by associating an overriding common active node address with the selected computer Application programs run ning at other nodes of the network utilize this active node address and thus interface with whichever sibling computer is identif
7. ATION OF A DORMANT SIBLING COMPUTER IN A COMMUNICATION NETWORK BY OVERRIDING A UNIQUE DORMANT NODE ADDRESS WITH A COMMON ACTIVE NODE ADDRESS TECHNICAL FIELD The present invention relates generally to a computer based communications network and more particularly to a method of operating a dormant sibling computer at a particular node of the communications network so that it may selectively be made accessible to application programs resident in other computers CROSS REFERENCE TO RELATED APPLICATIONS For a more comprehensive view of what is presently regarded as the best mode of practicing the invention and its intended environment reference should be made to the following commonly assigned U S patent appli cations filed concurrently herewith on Nov 2 1990 Detection and prevention of Duplicate Trading Transactions over a Communications Network U S patent application Ser No 07 608 642 Financial Exchange System Having Automated Recovery Rollback of Unacknowledged Orders U S patent application Ser No 07 608 643 Terminal for Automated Trading System having Streamlined User Interface U S patent applica tion Ser No 07 608 645 The following documents published by Quotron Sys tems Inc describe various aspects of a trading system which embodies many aspects of the present invention and which is available for commercial use under the trademark F X Trader Quotron F X Trader System Overview Winter
8. ION OF THE PREFERRED EMBODIMENT Referring initially to FIG 1 an exemplary network of trading terminals is shown The network comprises a plurality of city nodes C1 to C4 each connected to at 5 289 578 3 least one bank node B11 to B4M Each bank node is in turn connected to at least one trading terminal T111 to T3MN The bank and city nodes generally provide a routing network and supervisory functions to allow a trading terminal connected to one bank node to commu nicate with a trading terminal or trading terminals connected to another bank node or bank nodes The detail of the network structure is not important to an understanding of the present invention Suffice it to say that the city nodes may be located in any city and the city nodes may be connected in any combination neces sary to facilitate the routing of calls from city to city and from bank node to bank node For example the city nodes may be located in the cities indicated in FIG 1 wherein city node C1 is located in Tokyo city node C2 in New York city node C3 in Zurich and city node C4 in London The route over which messages are routed is invisible to the traders using the trading terminal For example a foreign exchange trader using the trading terminal T111 in Bank X in Tokyo can communicate with a foreign trader using the terminal T311 at Bank Y in Zurich The message from Bank X to Bank Y initiates at terminal 1111 is routed through the bank X bank node B11
9. S dollar USD the Great Britain pound GBP the Deutsche German mark DEM the Japanese yen JPY and the French franc FRF An incoming call queue panel 12 is also provided This panel prioritizes and displays the incoming calls arriving at the bank node to which the trading terminal is connected Calls may also be sent to a particular trader in which case this too is indicated in the incom ing call queue panel The remaining panels are conver sation panels 13 It is in these panels that conversations between traders take place The six conversation panels allow each trader to simultaneously conduct six trading transactions As shown in FIG 3 an exemplary duplex bank node B11 has a first and second sibling computer 16 and 17 respectfully such as MicroVAX computers a pair of 10 20 25 30 35 40 45 50 55 60 65 4 routers 18 and 19 such as DECrouter 200s and a switch 21 such as a DELNI The function of each component is conventional Briefly the routers route signals to and from other nodes The routers at the bank node route signals to and from a city node and to and from trading terminals corresponding to the bank node The switch allows either sibling computer to connect with either router In addition to these components the bank node com prises other conventional elements such as at least one monitor and keyboard not shown for operating the sibling computers modems 23 connected to t
10. United States Patent 1 Hartheimer et al O LLL US005289578A 1 Patent Number 5 289 578 45 Date of Patent Feb 22 1994 54 75 73 21 22 51 52 58 56 ACTIVATION OF A DORMANT SIBLING COMPUTER IN A COMMUNICATION NETWORK BY OVERRIDING A UNIQUE DORMANT NODE ADDRESS WITH A COMMON ACTIVE NODE ADDRESS Inventors Richard Hartheimer Morris Plains NJ Michael Coleman Sydney Australia Chris Klepka Parsippany N J Geoffrey Poole Sydney Australia Assignee Foreign Exchange Transaction Services Inc Long Island City N Y Appl No 612 045 Filed Nov 9 1990 US C ica 395 200 395 575 364 242 96 364 284 4 364 285 370 60 370 93 340 825 07 Field of Search 395 575 200 371 9 1 364 187 370 60 93 340 825 07 References Cited U S PATENT DOCUMENTS 4 775 976 10 1988 Yokoyama 371 9 4 823 256 4 1989 Bishop et al 395 575 4 920 484 4 1990 Ranade 395 200 4 926 375 5 1990 Mercer et al 395 575 4 975 838 12 1990 Mizuno et al 395 575 4 977 499 12 1990 Banning et al 395 200 4 985 830 1 1991 Atac et al 395 200 5 039 980 8 1991 Aggers et al 340 506 5 058 056 10 1991 Hammer et al 395 575 5 058 057 10 1991 Morita et al wee 395 575 5 077 655 12 1991 Jinzaki 395 200 5 086 384 2 1992 Fukada 3
11. a node administrator i e a person who administers the operation of the bank node FIG 4 shows an exem plary flow of commands the administrator makes as well as how the sibling computers react Recalling that both sibling computers cannot be ac tive at the same time the first step is for the administra tor to instruct the presently active sibling computer for example the first sibling computer 16 to go idle 26 i e to stop the system It should be understood that stop ping the system can be accomplished in many ways for example by saving trading data first or by stopping the system without saving any data These details are unim portant to the understanding of the present invention All that need be understood is that stopping the system results in the address of the sibling computer being changed from the active node address to its dormant address In the exemplary embodiment the presently active computer will prompt the administrator as to the length of time the computer should delay prior to going idle 27 Once this information is entered by the administra tor a warning message is displayed 28 at the trading terminals connected to the bank node An exemplary message is to warn the users that trading will be halted in X amount of time This gives the traders using the terminals time to close their trading communications Thereafter the presently active sibling computer stops 29 thus switching to its dormant mode The ad
12. ess Each sibling computer can commu nicate with the network using its dormant node address However a single active node address or published address is shared between the computers When one sibling computer is identified by the active node ad dress the other sibling computer is identified by its unique dormant address For example when the first sibling computer 16 is identified by the active node address the second sibling computer must be identified by its unique dormant address and vice versa It is important to note that each of the sibling comput ers is connected to the network and can communicate with the network regardless of whether it is in an active or dormant state This is of particular benefit because the operability of the dormant computer can be moni tored at any time since it is always part of the network Further since both of the sibling computers are al ways connected to the network switching between them is simplified Switching the active node address from one sibling computer to another may be required where the active computer fails thus necessitating the dormant computer to be activated Switching between sibling computers may also occur as a preventive mea sure such as where the active computer has a minor failure or where preventive maintenance must be per formed on the computer In an exemplary embodiment the switching of the sibling computers is accomplished by the commands of 5 289 578 5
13. he DECr outers for facilitating the input output connection of the DECrouters to other nodes and printers 22 con nected to the sibling computers In an exemplary embodiment the sibling computers run DECnet which is a communications software pack age Although a complete understanding of the opera tion of DECnet is not necessary for an understanding of the present invention it is helpful to understand that DECnet allows messages to be routed by means of the DECrouters between computers at different nodes of the network When DECnet is up and running at a bank node that node is available to the network to transmit and receive messages However when DECnet is down at a bank node that node is not available for transmis sion and reception of any messages and that node can be considered to be removed from the network At any one time when the bank node is functioning as a network element one of the sibling computers is active and the other is dormant and the network i e the other nodes in the network identifies the bank node through recognition of a published address installed on the active computer Although it is possible for both of the sibling computers to be dormant at the same time only one of the sibling computers can be active at any one time This condition is ensured by the present in vention More specifically each of the sibling computers has a unique address when in the dormant state i e its dor mant node addr
14. ied by the active node address Ac cordingly the dormant computer and its physical con nection to the network may be monitored by the com munications software using its unique dormant address and the dormant computer is always available to re place the active computer in a manner that is transpar ent to any other computers connected to other nodes of the network 2 Claims 6 Drawing Sheets Ban BANK NODES I I I t 1 1 1 i hB an ee e er ELSE CITY NODE CITY NODE CITY NODE JR I 1 I I r 1 J d I i L Tas his Tsin i t B Ba BANK NODES BANK Xi C4 BANK Y____ CITY NODE Th44 t Tai 1 1 i Bom Bou See G TERMINALS eee afta Sheet 1 of 6 5 289 578 Feb 22 1994 U S Patent SIVNINY3L T 91H Weg Weg a 1 NI i 3QON ALIO 3QON ALIO 2 c2 3QON ALIO vO S3QON ANVE Nra tg ua a 300N ALIO I I I l I i I t 2 I S300N INV8 Sheet 2 of 6 5 289 578 Feb 22 1994 U S Patent 08 01 7188 16 01 IBMN 6v 01 AHI 6r 01 3890 TEIR SS3490Nd NI AUVIYIV TIVI AYW ez asnoi Wadg asn 1vO8 eizi X3H10 W3g asn Waa asn IN3q asn MEE 3 s NAHO 7 18WO c xwv z 1VO8 nz y 310313S 92 9114 1 Qsn dgo VZ8N O O 4 3HI ASN Gc SL1Z 4 qsn d8g85 N3HO 91 019 W3q asn 9c S 9v1 Adr asn ZZ8S 91 1149 4 W3ag asn Or St 9vy Adr as
15. il a wait count is exceeded or to stop a re mote terminal ancillary control process if one is run ning These contingencies are particular to DECnet and are not unique to the present invention Further there may be situations where DECnet will not shutdown In these situations an error message is displayed indicating that the attempt to set the computer active has been aborted In any event DECnet must be shut down since the bank node must be removed from the network to change the addresses of the computers in the node Once DECnet is shutdown any network event process that is running is stopped the executor address is set to the active node address the executor name is set to the active node name and DECnet is re started 51 At this point the computer has been placed in an active state While the invention has been shown and described with reference to a presently preferred embodiment it is understood by those skilled in the art that numerous changes in form and detail may be made therein without departing from the scope of the invention For example while the present invention is described in relationship to the bank node of the foreign exchange trading system shown in FIG 1 it should be apparent that the principles of the invention is equally applicable 5 289 578 7 to any network having backup or sibling nodes It should also be understood that the city nodes described in conjunction with FIG 1 have sibling computers and
16. ministrator then invokes a start up procedure 31 on the previously dormant computer for example the second sibling computer 17 The start up procedure discussed in conjunction with FIGS 5A and 5B below results in replacing the dormant address of the second sibling computer with the active node address thus activating the second sibling computer The now active sibling computer is then available to receive and transmit mes sages to the terminals 32 connected to that bank node and trading may once again be allowed The administrator may conduct other operations during this process such as saving data stored on the first sibling computer 16 regarding recent trading activ ity and thereafter loading the saved information onto the second sibling computer 17 Preferably any bank or trader specific information such as transaction logs bank defined trading limits trader passwords and trader configuration preferences maintained by the active bank node computer is automatically backed up each night by copying it into the dormant sibling using the dormant computers permanent dormant address Referring now to FIGS 5A and 5B the addressing of each sibling computer is controlled carefully by the start up procedure of each sibling computer Each com puter has in its memory a signature file which contains information regarding the published address or active node address for the node the name of the node and the type of node in which the c
17. n OL 1 6049 1 W3a asn Sheet 3 of 6 5 289 578 Feb 22 1994 U S Patent e 1 B11 T112 C2 DECrouter 1111 DECrouter 18 21 Micro 16 VAX EE Modem Bank Node Fig 3 U S Patent Feb 22 1994 Sheet 4 of 6 5 289 578 ADMINISTRATOR INSTRUCTS ACTIVE NODE TO GO IDLE ACTIVE NODE PROMPTS ADMINISTRATOR AS TO TIME DELAY WARNING MESSAGE DISPLAYED AT TERMINALS CONNECTED TO BANK NODE ACTIVE NODE HALTS ADMINISTRATOR INVOKES STARTUP PROCEDURE ON IDLE NODE PREVIOUSLY IDLE NODE NOW ACTIVE SENDS MESSAGE TO TERMINALS CONNECTED TO BANK NODE Fig 4 U S Patent Feb 22 1994 Sheet 5 of 6 5 289 578 EXTRACT NODE TYPE AND ACTIVE NODE ADDRESS FROM SIGNATURE FILE 36 IS THE NODE A DUPLEX NODE CHECK REACHABILITY OF ACTIVE NODE ADDRESS IS ACTIVE NODE ADDRESS UNREACHABLE EXTRACT ACTIVE NODE NAME FROM SIGNATURE FILE U S Patent Feb 22 1994 Sheet 6 of 6 5 289 578 IS EXECUTOR ADDRESS DIFF FROM ACTIVE NODE ADD e STOP NETWORK EVENT LOGGER PROCESS IF RUNNING o SET EXECUTOR ADDRESS TO ACTIVE NODE ADDRESS o SET EXECUTOR NAME TO ACTIVE NODE NAME o START UP DECnet Fig 5B 5 289 578 1 ACTIV
18. nications network a first sibling computer currently using said common active node address and a second sibling computer currently using a respective said unique dormant address re assigning said common active node address to said second sibling computer and using said common active node address to re connect said second sibling computer to the communica tions network
19. omputer is connected in For example the node may contain only one computer or it may be a duplex node which contains a pair of sibling computers The present invention concerns only sibling computers resident in duplex nodes Thus when a computer is started up the node type and the active node address is extracted from the signa ture file 35 If the node is not a duplex node 36 then the Software does not have to invoke the method of the present invention and the method ends However if the node is a duplex node 37 the method continues and the active node address is checked for reachability 38 In other words the computer being started up tries to 20 25 35 40 45 50 55 60 65 6 access a computer node having the active node address if found in the signature file If such a computer can be reached 39 then there is already a computer in the duplex node that is in active status and the method ends to prevent both of the computers from being identified by the active node address For example if the second sibling computer 17 is being started up and it finds a computer in the node using the active node address then the first sibling computer 16 must already be ac tive If however a node having the active node address was not reached 41 then the active node address is available to be installed in the computer being started up Note that when the computers at the bank node are first started up these steps
20. ust be aware of the unique address of each computer in order to access it Prior art addressing schemes are generally cumber some For example in one scheme where a network has a main and backup computer at a first node and a plurality of other nodes the structure of the other nodes being unimportant the address that the other nodes use to access the two computers at the first node must be changed from the address of the main computer to the address of the backup computer However this puts a large burden on each of the network nodes to recognize when the addresses must be changed SUMMARY OF THE INVENTION The present invention provides a method for identify ing redundant sibling computers in a communications network having at least one node with a pair of sibling computers one normally active and the other normally dormant The sibling computer are identified by perma nently associating a unique dormant address to each sibling computer selecting one of the computers to be active and thereafter associating an overriding common active address to the selected computer Any applica tion programs running on the network need only spec ify the common active address for that particular node in order to interface with whichever sibling computer has been selected as the active computer at that node While one sibling computer is in active mode the other sibling computer must be in dormant mode The two sibling computers cannot be active
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