MS.NETGrid OGSI User Manual - EPCC
Contents
1. MySdeNamespace Create a new service data element ServiceData sde sde serviceDataSet_ Create sdeName code to populate the ServiceData object goes here MS NETGrid OGSIUserManual v1 0 22 Add service data element to the service data set serviceDataSet_ Add sde The indexer property of the ServiceDataSet can be used to access the ServiceData objects by the service data element s qualified name as show here Construct the qualified name for the service data element System Xml QualifiedName terminationTimeQName terminationTimeQName new System Xm1l QualifiedName terminationTime CoreConstants OGSI NAMESPACE URI Obtain the ServiceData object using the indexer ServiceData sd serviceDataSet_ terminationTimeQName can now use sd to access and alter the termination time service data element 9 3 The ServiceData class The ServiceData object is used to store the properties and values of the service data elements For full details of the ServiceData class see the class documentation this section provides an introduction to some of the mean features of the class 9 3 1 Service data element properties There are a number of standard OGSI properties that are associated with a service data element These are listed below along with their default values and corresponding property of the ServiceD2. The callback class must implement the IServiceDataValuesCallback interface This interface specifies a single read only property called ServiceDataValues that returns an array of objects that are the service data values For example class MyCallbackClass IServiceDataValuesCallback public object ServiceDataValues get code to create an object array of values goes her return result To specify that the callback mechanism should be used to determine the service data values the Callback property of the ServiceData class must be set to the instance of the callback class For example MyCallbackClass callbackInstance new MyCallbackClass sd Callback callbackInstance It is important to note that this mechanism for dynamic service data value creation can only be used when the service data element is non modifiable 9 3 4 Lifetime attributes Service data values can have lifetime attributes associated with them To add a service data value with specific lifetime values to a ServiceData object the overloaded AddValue method can be used There is a version of the method that takes lifetime values as well as the value object itself For example Create value object MyClass myObject new MyClass Create lifetime objects System DateTime goodFrom System DateTime Now System DateTime goodUntil Ogsi Core Util GridDateTime INFINITY System DateTime avail
3. Internet protocols such as HTTP and SOAP and described using WSDL Grid Services Web Services conforming to the OGSI specification Grid Service Instance A network accessible instance of an OGSI compliant service PortType A set of operations supported by a Web or Grid Service ServiceData An XML based mechanism that allows a client to query the state of a service instance in a flexible and extensible manner ServiceDataElement A particular element of serviceData identified by a name and a value Tomcat A container for Java based Web Applications http jakarta apache org AXIS A Web Application running under Tomcat which provides Web Services functionality http xml apache org Programming Model A set of procedures and APIs used to develop an application in a given domain MS NETGrid OGSIUserManual v1 0 30 References Documents referenced in the text and other related documents include the following MS NETGridOgsiDesignOverview MS NETGrid OGSI Implementation Design Overview MS NETGridOgsiDesignOverview v1 0 D Byrne EPCC June 16 2003 MS NETGrid Proj Def Project Definition for a Collaboration Between Microsoft and EPCC MS NetGrid ProjDef V2 0 M Jackson EPCC April 25 2003 OGSI Spec Open Grid Services Infrastructure Draft 29 S Tuecke K Czajkowski I Foster J Frey S Graham C Kesselman T Maquire T Sandholm D Snelling P Vanderbilt April 5th 2003 ht
4. Spec MS NET Grid OGSI User Manual Project Title Document Title Document Identifier NeSC National e Science Centre MS NETGrid MS NETGrid OGSI User Manual MS NETGrid OGSIUserManual v1 0 T Ha 0 all Authorship Ally Hume Document History Personnel Summary Version EPCC EPCC Approved 1 0 MJJ Second Draft Changes and Comments 0 2 ACH First Draft 0 1 Approval List EPCC Project Leader Technical Staff Technical Reviewers Coach Mike Jackson Daragh Byrne Ally Hume Ali Anjomshoaa Dave Berry Neil Chue Hong Approval List Microsoft Research Limited Managing Director University Relations x 3 Andrew Herbert Fabien Petitcolas Van Eden Dan Fay Copyright O 2003 The University of Edinburgh All rights reserved MS NETGrid OGSIUserManual v1 0 2 Contents A A sauce stsdecsesesseoteeesiecdcseoscraecteccssece saceeusesiass 2 O AAA 4 1 1 Product LicenCe ooocooonononocnnonenoninoninonnnconnconncconoconnconncono cono cona coca cono nono noconoonaconaccnnccn nos 4 1 2 Project AMAS VS O TO 4 1 3 Support and Queries cccccssscccscseecccscescccsssscecscsesccssssccesssesesccsssecesssessessesees 4 2 InstallatioN ocooocoonnconnconnocnnnconncnoncnoncnoncona cono conacononononconaconaconncconcconccnnnconc conc etsin cora cona conos 5 3 Running a Demonstration Client cssscssesscecccsscscccssccsssccesscccesccesesccesssssessessesees 6 4 Class
5. provide a pair of demonstration services These are located in the lt install_dir gt MS NETGrid Ogsi Container demoservices container The basicService subdirectory contains a persistent Grid Service that implements the GridService portType a transient version of this service and a factory for creating instances of the transient service The proxy code for these services is located in Ogsi Container services persistent and Ogsi Container services transient These services do not expose any additional functionality but do demonstrate the programming model that this document describes The counter subdirectory contains a more interesting example The transient service located in CounterServiceSimple cs exposes all the functionality of the GridService portType inherited from GridServiceSkeleton In addition Increment and Decrement methods are provided A serviceData element called count is defined with its own namespace The Increment and Decrement methods are used to alter the value of this serviceData element In addition the value of count may be set using the setServiceData operation provided by the GridService portType The deployment for the transient counter service and the persistent counter factory service may be examined in lt install_dir gt MS NETGrid Ogsi Container Web config The counter factory demonstrates the use of previously existing portTypes via the OgsiPortTypeAttribute attribute The CounterFactoryCre
6. documentation cooocoonnconncnonononcnonnonnnonanonanonanonanonnconaconnccnncconncnnnconc conc coc cona cono cona conos 7 5 Writing a simple persistent ServiC ooomommmmms 8 5 1 Write the service Class ooocoonooonnoconncnnncnoncnanonanonanonanonnnconnconncconcconncono cono ossosa nss ss seses 8 5 2 Write the proxy ClasS cccscscsscssscccccccescccssscrsnccsescccsesccesssceescccsescesssssersscsseseeses 9 5 3 Compile the service class and proxy class into an assembly csccsssscssseseeees 9 5 4 Write a asmx file for the Service oooooonoonnonononinoninonanoninononconaconncconcconccocconccono cono coss 10 5 5 Configure the OGSI container sesssesssesssesssessscsssesssesssessseossesssesssosssoossoossosssoosso 10 5 6 Installing the service sccsscsssscssssccccccesccecssccecscccesccesesceessccsssccssescessscserssessesees 10 6 Writing a client of a persistent Service ooooocommmssomsmm 12 7 Writing a transient service and a persistent Factory service ssscsssccssscsssceseoes 13 7 1 Write the transient service class ooocooomoonocnonoconnnonnnonocanoconconnccnncconcconcconnconccono cono coss 13 7 2 Write the persistent factory service ClaSS ssesssesssesssesssesssesssessesssoossocssoossoossoosso 14 7 3 Write factory creator class e sseessoesooesooessosssoessesssesssessseossesssosssesssosssocssoossoossoosso 14 TA Write proxy classes s iscscsssessceseecssssvessssossserasesenssssess
7. parameters o The creation parameters XML element is bundled inside a CreationType object that is passed as input to the factory s createService method o The Url property of all transient services proxies must be set before any methods of the proxy are called The Url property must be set to the handle returned by the factory via the LocatorType object o The transient service can be destroyed when the client is finished with it by calling the destroy method Compile this file along with MyTransService cs and MyTransServiceFactory cs as shown in the following command line csc out MyTransClient exe MyTransClient cs MyTransService cs MyTransServiceFactory cs This will produce an executable called MyTransClient exe that will use the factory to create a new instance of the transient Grid service and then call that service s hello method several times to producing the output shown below Have a service the locator is http localhost Ogsi Container services transient MyTransService asmx instanceld instance 141776660 214136689 104091352482151152689462196422965123173137 Ciao Mike 1 Ciao Daragh 2 Ciao Ally 3 MS NETGrid OGSIUserManual v1 0 21 9 Service data The concept of service data is an important part of OGSI The GridServiceSkeleton base class provides a collection for service data via the InstanceServiceData property Through this collection the service developer can manipulate the s
8. FactoryCreator cs is using System using System Xml using Ogsi Core namespace MyGridServices public class MyTransServiceFactoryCreator IFactoryCreator public GridServiceSkeleton CreateServiceObject XmlElement creationParams IServiceParameters factory MyTransServicelmpl retval string greeting hello creationParams is an XmlElement containing parameters to be used in the creation of the new service instance if creationParams null if creationParams Name initialValue throw new ArgumentException creationParams should be of type initialValue greeting creationParams ChildNodes 0 Value Create a new service instance retval new MyTransServicelmpl greeting Return the new service instance return retval The factory creator class must implement the IFactoryCreator interface This interface has only one method called CreateService0bject Essentially all this method has to do is create an instance of the transient service and return it The creationParams parameter of the CreateServiceObject method can be used to pass an arbitrary XML element from the client to the factory This is an ideal mechanism to use when the service class constructor requires one or more arguments This is the case in the code above the majority of the code is responsible f
9. TGrid OGSIUserManual v1 0 13 7 Writing a transient service and a persistent Factory service In this section we go through the stages required to write and deploy a simple transient Grid service with a corresponding persistent factory service The factory service can be used to create instances of the transient Grid service The stages are 1 Write the transient service class that implements the functionality of the transient service 2 Write the factory service class 3 Write the factory creator class that is used by the factory to create instances of the transient service 4 Write proxy classes for the service class and factory service class 5 Compile classes into an assembly 6 Write asmx files for the transient service and factory service 7 Configure the OGSI container 8 Install the services The transient Grid service we write here is very simple It is initialised with a single string argument called greeting provided to the factory service via the Factory portType CreateService operation that will create our transient Grid service and we will implement a single method called hello The method takes one argument called name and will return the string greeting name n where greeting is the value of the greeting argument the service was initialised with name is the value of the name argument of the hello method and n is an integer that starts at 1 and increments every time the method is called The Gr
10. The Ogsi Core PersistentGridServiceSkeleton and Ogsi Core GridServiceSkeleton classes give access to other Grid service infrastructure such as service data that the service may wish to use This simple example does MS NETGrid OGSIUserManual v1 0 9 not use service data 5 2 Write the proxy class The proxy class is used to expose the service s public methods or in other words the operations of the Grid service The code for the proxy class which should be saved in a file called MyService cs is as follows using System Web Services using Ogsi Container Instances Proxy namespace MyGridServices public class MyService PersistentGridServicelnstanceAspProxy WebMethod public string hello string name object args name return string CallMethod hello args This class inherits from the PersistentGridServiceInstanceAspProxy class in namespace Ogsi Container Instances Proxy The System Web Services WebMethodAttribute is used to tell ASP NET to expose this method as a public Web method of the service Other ASP NET method attributes may be used to provide further customisation See the ASP NET user documentation for details Every method that is to be exposed as part of the Grid service must have a corresponding method defined for it in the proxy class The methods in the proxy class are all very similar They simply put the arguments into an array and then pas
11. a new process NET Remoting The mechanism by which NET allows Remote Procedure Call RPC between AppDomains and between remote machines ASP Active Server Pages a Microsoft technology that works in conjunction with IIS to host Web Applications ASP NET The NET version of ASP with extensions for Web Services and Enterprise Applications C Pronounced C Sharp a new Microsoft programming language that takes advantage of NET platform features Assembly A collection of managed code which may form an executable or a library and may be distributed across a number of physical files Assemblies facilitate the separation of logical and physical resources OGSA The Open Grid Services Architecture which is a set of proposed architectures and protocols for Grid computing Anatomy OGSI The Open Grid Services Infrastructure a specification of behaviours and properties of Grid Services Physiology OGSI Spec OGSA DAI OGSA Data Access and Integration Grid Services framework for seamless access and integration of data using the OGSA paradigm OGSA DAJ MS NETGrid OGSIUserManual v1 0 29 Globus The Globus toolkit A standard toolkit of Grid software Version 3 will contain an implementation of OGSI in Java http www globus org WSDL The Web Services Description Language http www w3 org TR wsdl Web Services Refers to network enabled software capabilities accessed using common
12. ableUntil Ogsi Core Util GridDateTime INFINITY MS NETGrid OGSIUserManual v1 0 24 sd AddValue myObject goodFrom goodUntil availableUntil If no lifetime values are specified the goodFrom attribute defaults to the current time and the goodUntil and availableUntil attributes default to INFINITY It is possible to obtain the lifetime attributes associated with the values of a ServiceData object using the GetLifetimes method This method returns an array of ServiceDataAttributes objects each corresponding to a service data value The ServiceDataAttributes class has properties to get and set the lifetime attributes and also get and set the value to which the lifetime attributes are associated See the class documentation for classes ServiceData and ServiceDataAttributes for more details 9 3 5 Service data evaluators The grid service findServiceData and setServiceData operations are implemented by the GridServiceSkelton base class By default the findServiceData operation supports the queryByServiceDataNames query expression and the setServiceData operation supports the setByServiceDataNames and deleteByServiceDataNames query expressions It is possible to add new query expressions to these operations To add support for a new query expression you must implement a new query evaluator to evaluate the query Query evaluators must implement the IExpressionEvaluator interface The evaluator mus
13. ata class OGSI property Default value DataService property Minimum occurs inOccurs Maximum occurs axOccurs Mutability static utability Modifiable false odifiable Nillable false nillable 9 3 2 Service data values Service data elements can have zero or more values It is important to initialise a ServiceData object with details of the values that can be stored within it For example the following code configures a ServiceData object to store values of type MyClass Assume there is a ServiceData object called sd Specify that the ServiceData objects will store values of type MyClass sd ValuesType typeof MyClass Values can be added to the ServiceData using the AddValue method For example MS NETGrid OGSIUserManual v1 0 23 MyClass myObject new MyClass sd AddValue myObject There are several other methods and properties defined on the ServiceData class to manipulate the values of a service data element See the class documentation for more details 9 3 3 Using a callback to determine service data values dynamically In some instances it is preferably to calculate the service data values dynamically as and when they are needed rather than storing a collection of values in the ServiceData object This can be easily done by providing a callback class that the ServiceData class will use to determine the service data values whenever they are requested
14. ator class demonstrates the use of the IFactoryProvider interface The CreateServiceObject method takes an XML element with that specifies the initial value of the counter MS NETGrid OGSIUserManual v1 0 28 12 Glossary For convenience of reference we include the following glossary NET The Microsoft NET platform including the NET SDK Software Development Kit associated development tools such as Visual Studio NET http www microsoft com net and the Common Language Runtime Common Language Runtime a runtime environment that executes Microsoft Intermediate Language MSIL MSIL The NET bytecode a low level assembler like language executed by the Common Language Runtime Managed code Code that runs on the NET CLR IIS Microsoft Internet Information Server a web server offering communication over a variety of internet protocols ISAPI An Application Programming Interface API that allows applications to use the network services provided by IIS Commonly used to provide HTTP filters that respond to all HTTP requests on the server AppDomain NET allows the partitioning of a single Operating System process into a number of AppDomains which are essentially memory safe areas within the process If the code in an AppDomain crashes other AppDomains within the process are unaffected This concept has some performance advantages as using AppDomains avoids the overheads associated with starting
15. can be used in conjunction with a supplied client to test your installation The client is located in lt install_dir gt MS NETGrid CounterClient Go to the bin subdirectory and run the CounterClient executable Click on the Create New Counter button This creates a new instance of a transient counter service The Grid Service Handle for this service instance should appear in the Created counter handle box If it does not please make sure that IIS is running and the Ogsi Container directory is visible from Internet Services Manager Several operations may be performed on this service instance The count value may be set using the Set count value button This sets the current value of the counter to be that of the box to the left of this button The Increment and Decrement buttons may be used to adjust the value of the counter by the amount displayed in the box between the buttons The Find Service Data button can be used to obtain service data by name The count service data is found by default The ServiceData values are displayed in the bottom textbox If this client operates correctly the installation has been successful The correctly operating client looks like the following screenshot Counter A Counter factory url http localhost Ogsi Container services persistent CounterS erviceS impleF actory asmx Initial Value fo Create New Counter Created counter handle http localhost O0 gsi Container servic
16. eednsesuessssesssesesssuessssesssosissseateceses 15 7 5 Compile classes into an assembly scscsscssscccccscesccecssscesscccesccesescersseessessesees 17 7 6 Write asmx files for the transient service and factory service cccsceeees 17 7 7 Configure the OGSI container ccscsssscssccecccsesscscssccecssccesccssesceesssseessessesees 17 7 8 Install the Services wiccsscsccciececceascssssesssceacesstadssonssontcesenssscensestecessensseensoostsseasdcenacesens 18 8 Writing a client of a transient ServiCe ommoomomsmsmsms 19 MS NETGrid OGSIUserManual v1 0 3 E A O O 21 9 1 Default service data elements oocoonmommosiosiaconnccnnccnnnconnconnconocono cono coonconaconaconnccnnoss 21 9 2 Service data SOt cooocooonconncnonononnnonnnononnnconaconaccnncconcconocono cono cono conc cona nono nono cooncconaccn ccoo nos 21 9 3 The ServiceData Class s c ccciccissnisscrsscscccesessssnevccscndeenivconesodscesscesscensooddvebecesncceeanste 22 9 3 1 Service data element properties ccccccccssescccsscercscsccsccssssccessseessecsesees 22 9 3 2 Service data Values ccccccsccssscssscssscsssscssscssscssssssssssssssssssssssssssesssscssssseeses 22 9 3 3 Using a callback to determine service data values dynamically 23 9 3 4 Lifetime attributes ooomooenosoonnnsonncoonncnonnnonocnnnocccoonncononncnoonocoor conoce rooccncocnnonnos 23 9 3 5 Service data evaluators cccccccrcsssc
17. ersistent service Writing a client to talk to a persistent Grid Service is identical to writing a client to talk to a Web Service Firstly we must create a proxy class for the service and then use it in our own code To create a proxy class create a new directory and within that directory use the following command line instruction WSDL http localhost O gsi Container services persistent My Service asmx If you are accessing our container from a remote host then you can replace localhost with the name of the host upon which our container is running This will create a proxy class called MyService cs We can now write a client that uses the service Code for an example client of our service is using System class MyClient static void Main MyService GridService new MyService Console WriteLine GridService hello Horace Compile this file along with the MyService cs file as shown in the following command line instruction csc out MyClient exe MyClient cs MyService cs This will produce an executable called MyClient exe that will call the Grid service s hello method when it is run producing the output shown below C Projects ogsanet client gt MyClient hello Horace 1 C Projects ogsanet client gt MyClient hello Horace 2 C Projects ogsanet client gt MyClient hello Horace 3 MS NE
18. ervice data in many ways This section describes how the developer can manipulate the service data 9 1 Default service data elements All services will have several service data elements by default These are defined by the OGSI specification and are implemented in the GridServiceSkeleton base class The default service data elements are o interface o factoryLocator o gridServiceHandle o gridServiceReference o findServiceDataExtensibility o setServiceDataExtenstbility o terminationTime o serviceDataName 9 2 Service data set The GridServiceSkeleton base class provides a protected member variable through which service implementations can access the service data collection This member variable is called serviceDataSet_ and is of type ServiceDataSet The service data set is a container for service data elements Each service data element is referenced by an XML qualified name consisting of a local name and a namespace The ServiceDataSet class provides methods to create new service data elements add service data elements to the collection access service data elements from the collection as well as several others See the class documentation for full details of the class New service data elements can be added to the collection with code similar to the following Construct a qualified name for the service data element System Xml XmlQualifiedName sdeName new System Xml XmlQualifiedName mySdeName
19. es transient CounterS erviceS imple asmx instancel d instance 1 285907 72 887167421 21971 28332502051 112421161697994160139 o Set count value Decrement fi Increment Destroy service instance Service data to find count gridServiceHandle Find Service Data lt serviceDataWalues xmins xsd http www w3 org 2001 lt MLSchema xmins xsi http 77v 3 0192001 MLS chema instance xmins http 4 gridforum org namespaces 2003 03 0GS5I gt 1 lt count xmins http localhost CounterNS d2p1 goodFrom 2003 06 16T 09 44 47 2422 001ra d2p1 goodUntil infinity d2p1 availableUntil infinity mins d2p1 http 2 gridforum org namespaces 2003 03 0G51 gt 5 lt count gt lt gridServiceHandle xmins http 4 gridforum org namespaces 2003 03 0G5 d2p1 g00dFrom 2003 06 16T09 44 55 5392 001 ra d2p1 goodUntil infinity MS NETGrid OGSIUserManual v1 0 4 Class documentation Source code documentation is available in Microsoft Help format at lt install dir gt MS NETGrid doc API MS NETGridHelp chm MS NETGrid OGSIUserManual v1 0 8 5 Writing a simple persistent service In this section we go through the stages required to write and deploy a simple persistent Grid service These stages are 1 Write the service class that implements the functionality of the service 2 Write the proxy class that exposes the service s public methods 3 Compile the service class and proxy cla
20. file called MyTransServiceFactoryImpl cs is as follows using System using Ogsi Core namespace MyGridServices OgsiPortType typeof FactoryPortType http localhost MyTransServiceFactoryNs MyTransServiceFactoryPortType public class MyTransServiceFactorylImpl PersistentGridServiceSkeleton As can be seen this is a very simple class The class is for a persistent service so it inherits from Ogsi Core PersistentGridServiceSkeleton The service is to be a factory so the we have used the OgsiPortType attribute to specify that the service supports the Factory portType When we use the OgsiPortType attribute to specify that a service supports the Factory portType the majority of the implementation is done for us all we have to do is write a creator class to create instances of the service the factory creates and then specify that the creator class is associated with the factory These tasks are covered in sections 7 3 and 7 7 respectively The second and third arguments to the OgsiPortType attribute specify the namespace and name of the portType These values are not used in the current release but are intended to provide a reference to the portType for use in future releases 7 3 Write factory creator class The factory creator class is used to create instances of transient services The code which MS NETGrid OGSIUserManual v1 0 15 should be saved in a file called MyTransService
21. for the service 5 5 Configure the OGSI container For each Grid service hosted by the OGSI container an entry must be added to the container s Web config file this file is located at lt oGSIContainer gt Web config Inside the lt gridServiceDeployment gt element of the file add the following entry lt gridServiceDeploymentDescriptor asmxProxyFileName MyService asmx serviceClass MyGridServices MyServicelmpl assembly MyServices persistence persistent gt lt gridServiceDeploymentDescriptor gt This entry specifies o The name of the asmx file generated in section 5 4 for example MyService asmx o The full name of the service class created in section 5 1 for example MyGridServices MyServicelmpl o The name of the assembly created in section 5 3 for example MyServices o Whether the service is persistent or transient 5 6 Installing the service To install the service o Copy the MyServices d11 assembly to lt OGSIContainer gt bin o Copy the MyService asmx file to lt OGSIContainer gt services persistent o Restart IIS To restart IIS obtain the control panel select Administrative Tools and then select Internet Services Manager Select the appropriate web site probably Default Web Site and use the stop and start icons to MS NETGrid OGSIUserManual v1 0 11 stop and restart the server MS NETGrid OGSIUserManual v1 0 12 6 Writing a client of a p
22. general and ASP NET in particular to the development of Grid services rather than as a fully functioning product In consequence we do not provide any support for our software However please feel free to forward any comments queries suggestions or problems you have to ogsanet queries epcc ed ac uk MS NETGrid OGSIUserManual v1 0 2 Installation The download consists of a zip file called Ms N convenient directory of your choice At this ETGridOGSI TP1 0 zip Extract this to a location there will be a directory called MS NetGrid This directory will have a number of subdirectories one of which is called Ogsi Container This Ogsi Container directory contains the ASP NET based OGSI container as well as all source code for the container The Ogsi Container directory must be set up as a virtual directory under Internet Information Services IIS This can be done using Microsoft s Internet Services Manager see the user documentation for this product for details of creating a virtual directory Call the virtual directory Ogsi Container Throughout the rest of this document the notation lt OGSIContainer gt refers to the full path name of the Ogsi Container directory lt inst the MS NETGrid directory was unzipped all_dir gt refers to the directory into which MS NETGrid OGSIUserManual v1 0 6 3 Running a Demonstration Client The installation is configured to initialise a counter service factory that
23. id service will inherit additional methods e g findServiceData and destroy that correspond to the GridService portType operations that all Grid services must provide 7 1 Write the transient service class The service class is the class that implements the specific functionality of the Grid service The code for this class which should be saved in a file called MyTransServiceImpl cs is as follows using Ogsi Core namespace MyGridServices public class MyTransServiceImpl GridServiceSkeleton private int count _ oh private string greeting public MyTransServicelmpl string greeting greeting greeting MS NETGrid OGSIUserManual v1 0 14 public string hello string name return greeting name o count_ ToString This class inherits from the Ogsi Core GridServiceSkeleton class All transient Grid services must inherit from this class The most interesting feature of this class is that the constructor takes an argument We therefore require a mechanism to allow the client to pass this parameter to the factory that will create the service instances This mechanism will be explained in more detail in section 7 3 7 2 Write the persistent factory service class The factory service class is the class that implements the functionality of the persistent factory service The code which should be saved in a
24. nt this is used to create the service instance XmlDocument doc new XmlDocument XmlElement xmlParams doc CreateElement initialValue Xml1Node val doc CreateTextNode Ciao xmlParams AppendChild val Construct a creation object MyTransServiceFactoryNS CreationType creation creation new CreationType creation terminationTimeSpecified false creation serviceParameters xmlParams Create a service using the factory MyTransServiceFactoryNS LocatorType locator locator factoryService createService creation Console WriteLine Have a service the locator is n locator handle 0 MS NETGrid OGSIUserManual v1 0 20 Create service object MyTransService service new MyTransService Tell this service object the location of the service instance service Url locator handle 0 Use the service object Console WriteLine service hello Mike y Console WriteLine service hello Daragh Console WriteLine service hello Ally IS E Destroy the transient service when finished Service destroy There are several points to note about the code o We construct an XML element called xm1Params that contains the data required by the factory creator class The schema of this element is specific to this particular factory other factories can use different schema for their creation service
25. ntiated by the container instances of every class defined MS NETGrid OGSIUserManual v1 0 26 by its OgsiPortTypeAttributes are created and associated with the service instance When developing proxy methods for provider based methods the Cal1MethodOnProvider method of GridServiceInstanceAspProxy is used WebMethod public int SomeOtherUsefulMethod return CallMethodOnProvider MyAssembly SomeUsefulClass SomeUsefulMethod object null 7 The provider classes can be given access to the ServiceDataSet of the service in the following manner If the provider classes are found to implement IOperationProvider the ServiceInstance property defined by this interface is initialised with a reference to the instance of MyService that it is associated during initialisation We provide a basic implementation of IOperationProvider called Ogsi Core OperationProviderBase for convenience The provider class may now access the service s ServiceDataSet by obtaining a reference from the reference it maintains to the service class public class SomeOtherUsefulClass OperationProviderBase public int SomeOtherUsefulMethod int i process this ServicelInstance InstanceServiceData someQName i return 1 MS NETGrid OGSIUserManual v1 0 27 11 Example services As an example of using portTypes serviceData and persistent and transient services we
26. o lt OGSIContainer gt services transient o Copy the MyTransServiceFactory asmx file to lt OGSIContainer gt services persistent o Restart IIS MS NETGrid OGSIUserManual v1 0 19 8 Writing a client of a transient service Writing a client to talk to a transient Grid Service is virtually identical to writing a client to talk to a Web Service Firstly we must create a proxy classes for the services and then use them in our own code To create proxy classes create a new directory and within that directory issue the following command line commands each should be entered on a single line WSDL namespace MyTransServiceNS http localhost Ogsi Container services transient MyTransService asmx WSDL namespace MyTransServiceFactoryNS http localhost Ogsi Container services persistent MyTransServiceFactory asmx This will create proxy classes called MyTransService cs and MyTransServiceFactory cs each within their own namespace to avoid name clashes with common types We can now write a client that uses the factory and the service instances it creates The code for the client is save this in a file called MyTransClient cs using System using System Xml using MyTransServiceNs using MyTransServiceFactoryNs class MyTransClient static void Main Create a factory service object MyTransServiceFactory factoryService new MyTransServiceFactory Construct XML creation eleme
27. on return LocatorType CallMethodOnProvider Ogsi Core FactoryPortType CreateService arguments This class uses the CallMethodOnProvider method rather than the CallMethod method In this case Cal 1MethodOnProvider is used as the CreateService method is not defined MS NETGrid OGSIUserManual v1 0 17 directly on MyTransServiceFactoryImp1 but on the FactoryPortType provider object associated with MyTransServiceFactoryImpl using OgsiPortTypeAttribute The first argument to CallMethodOnProvider is the name of the object type and is used to select the appropriate provider The second argument is the name of the method to call and the third argument is the parameters to pass to the method 7 5 Compile classes into an assembly To compile all the classes into an assembly use the following command line this should be typed on a single line csc t library out MyTransServices dll MyTransService cs MyTransServiceFactory cs MyTransServiceFactoryCreator cs MyTransServiceFactoryImpl cs MyTransServicelmpl cs v lt OgsiContainer gt bin Ogsi Container dll Where lt 0GSIContainer gt is the path to the OGSI container installation 7 6 Write asmx files for the transient service and factory service To utilise ASP NET to deploy our Grid service we must create a asmx file for the transient service and the factory service As in the case of the persistent service this simply maps the service name to
28. or extracting the value for the constructor s greeting argument from the XML element 7 4 Write proxy classes Proxy classes are required to expose the services public methods We have to write proxy MS NETGrid OGSIUserManual v1 0 16 classes for both the transient service and the factory service The code for the service class s proxy class which should be saved in a file called MyTransService cs 1s using System Web Services using Ogsi Container Instances Proxy namespace MyGridServices public class MyTransService TransientGridServicelnstanceAspProxy WebMethod public string hello string name object args name return string CallMethod hello args This class is virtually identical to the proxy class for the persistent service discussed in section 5 2 The only difference here is that this class inherits from TransientGridServiceInstanceAspProxy because it is a transient rather than persistent service The code for the factory class s proxy class which should be saved in a file called MyTransServiceFactory cs Is using System Web Services using Ogsi Container Instances Proxy using Ogsi Core Types namespace MyGridServices public class MyTransServiceFactory PersistentGridServicelnstanceAspProxy WebMethod public LocatorType createService CreationType creation object arguments creati
29. s these arguments and the method name to the Cal1Method method that is a public method of the base class 5 3 Compile the service class and proxy class into an assembly To compile the service class and proxy class into an assembly use the following command line instruction which should be typed on a single line esc t library out MyServices dll MyServiceImpl cs MyService cs v lt OGSIContainer gt bin Ogsi Container dll lt OGSIContainer gt is the path to the OGSI container installation If you are using the Microsoft Visual Studio development environment configure your project to output an assembly called MyServices d11 You will have to add the following references to the project before building o lt OGSIContainer gt bin Ogsi Container dll o System Web Services dll MS NETGrid OGSIUserManual v1 0 10 Regardless of whether you have used Visual Studio or the command line you should now have created an assembly called MyServices d11 located in the current directory You need to copy this dll to lt OGSIContainer gt bin 5 4 Write a asmx file for the service To utilise ASP NET to deploy our Grid service we must create a asmx file for the service This simply maps the service name to the proxy class The asmx file is save this in a file called MyService asmx lt S WebService Class MyGridServices MyService S gt The name of the asmx file determines the Grid Service Handle GSH
30. sServices persistence persistent gt lt The type of the service object to create gt lt serviceParameter name creationProvider value MyGridServices MyTransServiceFactoryCreator MyTransServices gt lt gridServiceDeploymentDescriptor gt The majority of this element is very similar to that for the transient service The lt serviceParameter gt element is new This element specifies a parameter that is passed to the service In this case the parameter name is creationProvider The parameter value is the name of the factory creator class that this factory service must use to create service instances followed by a comma followed by the name of the assembly containing the class This lt serviceParameter gt element therefore associates the creator class with the service factory that uses it The final piece of configuration that must be carried out is to set the domain name that is used when creating transient services This is simply the domain name of the machine running IIS Edit the following line in the Web config file found in the configuration gridContainer config containerProperties section and set the value field to the appropriate domain name e g www epcc ed ac uk lt add key domain value localhost gt 7 8 Install the services To install the service o Copy the MyTransServices dl1 assembly to lt OGSIContainer gt bin o Copy the MyTransService asmx file t
31. ss into an assembly 4 Writea asmx file for the service 5 Configure the OGSI container 6 Install the service The Grid service we write here will be a persistent Grid service We will implement a single method called hello This method takes one argument called name and will return the string hello name n where name is the value of the name argument and n is an integer that starts at 1 and increments every time the method is called The Grid service will inherit additional methods e g findServiceData and destroy that correspond to the GridService portType operations that all Grid services must provide 5 1 Write the service class The service class is the class that implements the specific functionality of the Grid service The code for this class is as follows and should be saved in a file called MyServiceImpl cs using Ogsi Core namespace MyGridServices public class MyServicelmpl PersistentGridServiceSkeleton private int count_ 1 public string hello string name return hello name count _ ToString This class inherits from the Ogsi Core PersistentGridServiceSkeleton class All persistent Grid services must inherit from this class In contrast transient Grid services must inherit from the Ogsi Core GridServiceSkeleton class As can be seen from the code implementing the service class for a Grid service is very similar to writing any other class
32. sssccssscssscssscsssensssssssssssssesssscssscsssssssses 24 10 POPt Ty PeSiccinncscsescscessstevecessecvosussGeonseseccseeussdeduossdeonseduadesnsaSosstesssededcensesusessebdeccdasecexasesess 25 10 1 OgsiPortTypeAttribute ccccscscsscssccccccscccssesccessscersssseesscscescesssscersssssesceseese 25 11 Example services lt scssssescecsaceseesdscoassssccesennssoossessocesecnicesasasssnsoenscesedaddersseoveceseunsdccaseoses 27 12 GIOSSATY wessscses ckscisecvscsuscseadaseesnovestescdsadsetnnesuosssosessednndcecasebssssoenasdecessedesbeswubossecseecdveseness 28 A O 30 MS NETGrid OGSIUserManual v1 0 4 1 Introduction MS NET Grid is an ASP NET based implementation of the Open Grid Services Infrastructure This user manual is aimed at the Grid service developers and describes how to use the MS NET Grid implementation to create Grid services Details of how to write clients that use these services in the form of running examples are also included This document complements MS NETGridOgsiDesignOverview that is included with this distribution 1 1 Product Licence The MS NETGrid software is released under the licence described in LICENSE TXT under the root directory of the distribution 1 2 Project WWW Site The MS NET Grid Project WWW site is at http www epcc ed ac uk ogsanet 1 3 Support and Queries Please note that our software is intended as a proof of concept to demonstrate the applicability of Microsoft NET in
33. t then be added to the query engine The GridServiceSkeleton base class has a protected member variable queryEngine_ of type Ogsi ServiceData Query QueryEngine This class has a method RegisterEvaluator that can be used to add a query evaluator to the query engine For examples of query evaluators see the implementations of QueryByServiceDataNamesEvaluator and SetByServiceDataNamesEvaluator both in the Ogsi ServiceData Query namespace MS NETGrid OGSIUserManual v1 0 25 10 PortTypes A large portion of OGSI Spec addresses the issue of services providing multiple portTypes and allowing services to inherit from multiple portTypes In our approach the WebMethodAttribiute marked methods in the proxy classes essentially represent the most derived portType for a service and it is with this that the clients communicate At present 1t is only possible to present this most derived portType to the client It is possible to alter the properties and namespaces of the exposed operations by using the WebServiceAttribute SoapDocumentMethodAttribute and SoapRpcMethodAttribute classes and others provided by the NET framework See the NET user documentation for details We address the issue of portType re use in the following manner When developing a service implementation service methods may be placed on the class you derive from GridServiceSkeleton like so public class MyService PersistentGridServiceSkele
34. the proxy class The asmx file for the transient service is save in file MyTransService asmx lt S WebService Class MyGridServices MyTransService gt The asmx file for the factory service is save in file MyTransServiceFactory asmx lt S WebService Class MyGridServices MyTransServiceFactory gt 7 7 Configure the OGSI container For each Grid service hosted by the OGSI container an entry must be added to the container s Web config file this file is located at lt oGSTContainer gt Web config For the transient service the following entry must be added to the lt gridServiceDeployment gt element of the Web config file lt gridServiceDeploymentDescriptor asmxProxyFileName MyTransService asmx serviceClass MyGridServices MyTransServicelmpl assembly MyTransServices persistence transient gt lt gridServiceDeploymentDescriptor gt This contents of this element are similar to that shown in section 5 5 for the simple persistent service Notice the value of the persistence attribute is now transient For the factory service the following element must be added to the lt gridServiceDeployment gt element of the Web config file lt gridServiceDeploymentDescriptor asmxProxyFileName MyTransServiceFactory asmx MS NETGrid OGSIUserManual v1 0 18 serviceClass MyGridServices MyTransServiceFactorylmpl assembly MyTran
35. ton public string myMethod this InstanceServiceDataSet someQName 10 return hello With this method access to the service s ServiceDataSet is via the InstanceServiceData property inherited from GridServiceSkeleton Adding methods in this manner essentially means adding methods to a base service portType In other circumstances it may be desirable to use functionality developed elsewhere to provide operations or to logically group related functionality into single portTypes which you then wish to aggregate on your service We provide means of doing this using the Ogsi Core OgsiPortTypeAttribute and Ogsi Core OperationProviderBase classes and the Ogsi Core IOperationProvider interface 10 1 OgsiPortTypeAttribute We use as an example a class SomeUsefulClass with a method SomeUsefulMethod It is desired to expose this method as an operation on your service The simplest way to do this is as follows OgsiPortType typeof MyAssembly SomeUsefulClass http mydomain com myNameSpace UsefulPortType public class MyService PersistentGridServiceSkeleton The first parameter in the attribute is the type of your provider class The second parameter is the URI of the namespace for this new portType The third parameter is the name of the portType The latter two parameters do not have an effect at the moment but are included for possible future work When the MyService class is insta
36. tp www gridforum org ogsi wg Virginia Impl OGSILNET An OGSI compliant Hosting Container for the NET Framework Grid Computing Group University of Virginia WWW site http www cs virginia edu humphrey GCG ogsi net html GTk3 Globus Toolkit version 3 and OGSI Available at http www globus org ogsa Physiology The Physiology of the Grid Draft 2 9 I Foster C Kesselman J Nick S Tuecke Available at http www gridforum org org ogsa wg Anatomy The Anatomy of the Grid Foster C Kesselman S Tuecke Available at http www gridforum org ogsa wg OGSA DAI Open Grid Service Architecture Database Access and Integration http www ogsadal org uk WSDL Spec Web Services Description Language 1 1 http www w3 org TR 2001 NOTE wsdl 20010315 AXIS The Apache Axis SOAP Engine http ws apache org axis
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