1. Web Service Resource Framework Creating Globus 4 services
Grid Computing, B. Wilkinson, 2005

2. GT 4 services
Key aspect is the separation of the (web) service and a resource – conceptually if not actually.
Provides the ability to have “state” without altering the statelessness of a web service.

3. Example with a “database” resource
The Grid 2: Blueprint for a new Computing Infrastructure, Ian Foster, Carl Kesselman and Steve Tuecker Editors, Morgan Kaufmann Chapter 17: “The Open Grid Service Architecture,” by Ian Foster, Carl Kesselman and Steve Tuecker.

4. In this example, the client accesses a file transfer service to perform actions such as transfer a file from one storage service to another.
Because based upon web services, uses web services technology, XML, WSDL, etc.

5. Web Service Resource Framework
(WS-RF)
Resource
Web Service
Resource properties
Holds information retained between accesses.
Client

6. Key XML files needed for implementing service
WSDL file – defines the service interface.
Deployments files:
WSDD deployment file
JNDI deployment file

7. Service interface file
Container
Deployment files
WSDD, JNDI files
Resource
Service interface file
WSDL file
Web Service
Resource properties
Holds information retained between accesses.
Client

8. WSDL file
Serves the same purpose as the WSDL file in web services – to define the service interface.
A significant addition in the WSDL file is to specify the resource.

9. Service interface
If service implements operations on WSRF resource properties, WSDL will include definitions relating to resource property.
The binding component to specify how abstract interface maps to concrete protocol messages generated by GT4 automatically.

10. Service implementation
If service uses WSRF mechanisms, implementation must include code for resource implementation and resource home.
Resource home – manages resources

11. Globus-specific features of WSDL
Resource properties – specified in portType attribute wsrp:ResourceProperties
WSDL preprocessor used to include WSRF definitions (portType attribute wsdlpp:extends).
Bindings – not needed in WSDL because automatically inserted by GT4 when built
Developed from page 31 of Sotomaytor’s GT4 tutorial

12. WSDL file used for GT 4 service in Assignment 2

13. Purpose of Service in Assignment 2
To store an integer value which can be acted upon by methods to:
Get its value
Increment its value (add one), and
Decrement its value (subtract one).
The service is stateful (the value is retained between accesses).

14. <?xml version="1.0" encoding="UTF-8"?>
<definitions name="MathService"
targetNamespace=
MathService_instance
xmlns="
xmlns:tns=
xmlns:wsdl="
xmlns:wsrp="
wsrf-WS-ResourceProperties-1.2-draft-01.xsd"
xmlns:wsrpw="
wsrf-WS-ResourceProperties-1.2-draft-01.wsdl"
xmlns:wsdlpp="
WSDLPreprocessor"
xmlns:xsd="
<wsdl:import namespace=
"
location="../../wsrf/properties/WS-ResourceProperties.wsdl" />

15. <types>
<xsd:schema targetNamespace="
MathService_instance"
xmlns:tns="
xmlns:xsd="
<!-- REQUESTS AND RESPONSES -->
<xsd:element name="add" type="xsd:int"/>
<xsd:element name="addResponse">
<xsd:complexType/>
</xsd:element>
<xsd:element name="subtract" type="xsd:int"/>
<xsd:element name="subtractResponse">
<xsd:element name="getValueRP">
<xsd:element name="getValueRPResponse" type="xsd:int"/>

16. <!-- RESOURCE PROPERTIES -->
<xsd:element name="Value" type="xsd:int"/>
<xsd:element name="LastOp“ type="xsd:string"/>
<xsd:element name="MathResourceProperties">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="tns:Value“ minOccurs="1“
maxOccurs="1"/>
<xsd:element ref="tns:LastOp“ minOccurs="1“
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema>
</types>

17. <!- M E S S A G E S -->
<message name="AddInputMessage">
<part name="parameters" element="tns:add"/>
</message>
<message name="AddOutputMessage">
<part name="parameters" element="tns:addResponse"/>
<message name="SubtractInputMessage">
<part name="parameters" element="tns:subtract"/>
<message name="SubtractOutputMessage">
<part name="parameters" element="tns:subtractResponse"/>
<message name="GetValueRPInputMessage">
<part name="parameters" element="tns:getValueRP"/>
<message name="GetValueRPOutputMessage">
<part name="parameters" element="tns:getValueRPResponse"/>

18. <!-- P O R T T Y P E -->
<portType name="MathPortType"
wsdlpp:extends="wsrpw:GetResourceProperty"
wsrp:ResourceProperties="tns:MathResourceProperties">
<operation name="add">
<input message="tns:AddInputMessage"/>
<output message="tns:AddOutputMessage"/>
</operation>
<operation name="subtract">
<input message="tns:SubtractInputMessage"/>
<output message="tns:SubtractOutputMessage"/>
<operation name="getValueRP">
<input message="tns:GetValueRPInputMessage"/>
<output message="tns:GetValueRPOutputMessage"/>
</portType>
</definitions>

19. Service Code The code has two major parts: Resource properties
Service code (methods)
which are combined into one file for this assignment.

20. Service – Resource Properties
public class MathService implements Resource, ResourceProperties {
private ResourcePropertySet propSet; /* Resource Property set */
private int value;
private String lastOp;
public MathService() throws RemoteException { /* RP Constructor */
this.propSet = new SimpleResourcePropertySet(
MathQNames.RESOURCE_PROPERTIES); /* Create RP set */
try { /* Initialize the RP's */
ResourceProperty valueRP = new
ReflectionResourceProperty(
MathQNames.RP_VALUE, "Value", this);
this.propSet.add(valueRP);
setValue(0);
ResourceProperty lastOpRP = new
MathQNames.RP_LASTOP, "LastOp", this);
this.propSet.add(lastOpRP);
setLastOp("NONE");
} catch (Exception e) {
throw new RuntimeException(e.getMessage()); }
Resource properties
Resource Property code

21. Resource and ResourceProperty interfaces
Resource – a way of tagging a class as being a resource. This interface does not require any methods.
ResourceProperty – interface representing a single resource property
ReflectionResourceProperty -- A GT4 class, one of the ways one can represent a resource property in GT 4.

22. Service – Resource Properties methods
/* Get/Setters for the RPs */
public int getValue() {
return value; }
public void setValue(int value) {
this.value = value;
public String getLastOp() {
return lastOp;
public void setLastOp(String lastOp) {
this.lastOp = lastOp;

23. Service code - methods
/* Remotely-accessible operations */
public AddResponse add(int a) throws RemoteException {
value += a;
lastOp = "ADDITION";
return new AddResponse(); }
public SubtractResponse subtract(int a) throws RemoteException {
value -= a;
lastOp = "SUBTRACTION";
return new SubtractResponse();
public int getValueRP(GetValueRP params) throws RemoteException {
return value;
/* Required by interface ResourceProperties */
public ResourcePropertySet getResourcePropertySet() {
return this.propSet;

24. Deploying a GT 4 service
The GT 4 container uses Apache Axis and the basic steps for deploying a service are similar to that described earlier for Apache Axis in assignment 1, with some slight differences.

25. Deployment files
 server-config.wsdd (Web Service Deployment Descriptor) - contains information about the web service.
jndi-config.xml (JNDI configuration file) - contains information about the resource management.

26. WSDD file <?xml version="1.0" encoding="UTF-8"?>
<deployment name="defaultServerConfig"
xmlns="
xmlns:java="
xmlns:xsd="
<service name="examples/core/first/MathService" provider="Handler" use="literal" style="document">
<parameter name="className"value="org.globus.examples.
services.core.first.impl.MathService"/>
<wsdlFile>share/schema/examples/MathService_instance/Math_service.wsdl
</wsdlFile>
<parameter name="allowedMethods" value="*"/>
<parameter name="handlerClass“
value="org.globus.axis.providers.RPCProvider"/>
<parameter name="scope" value="Application"/>
<parameter name="providers" value="GetRPProvider"/>
<parameter name="loadOnStartup" value="true"/>
</service>
</deployment>

27. <service name="examples/core/first/MathService" provider="Handler" use="literal" style="document">
specifies where the service will be located.

28. JNDI deployment file
<?xml version="1.0" encoding="UTF-8"?> <jndiConfig xmlns="
<service name="examples/core/first/MathService">
<resource name="home“
type="org.globus.wsrf.impl.ServiceResourceHome">
<resourceParams>
<parameter>
<name>factory</name>
<value>org.globus.wsrf.jndi.BeanFactory</value>
</parameter>
</resourceParams>
</resource>
</service>
</jndiConfig>

29. Steps for developing GT4 service
Define service interface using WSDL
Implement service
Include routines for associated resources
Define deployment using WSDD file
Compile everything.
Deploy service, either using:
GT4 globus-build-service script, or
ant directly

30. ant (Another Neat Tool)
A build tool used in this assignment for deploying service.
Similiar to the make program but the dependencies are specified using XML configuration files.

31. globus-build-service
GT 4 build command
globus-build-service
Contains bash and ant files, see globus service build tools:

32. Resource Home Resources are managed by “Resource Homes”
Provides an interface for adding and removing resources

33. Resource Home Resource home Web Service Client Resource create/
find resource
Web Service
Client
Manages
Methods operate on resources properties
Resource

34. Resource Home Resource home Web Service Client Resource
Previously, service and resource in one file
and resource home limited to one resource,
using ServiceResourceHome class

35. Resource Home Resource home Web Service Client Resource
Separating service and resource in different file,
have 3 files the service, the resource home, and the resource.
Implement by extending SingletonResourceHome class.

36. Multiple Resources
Can use a service called a factory service for creating resources
Each resource will be assigned a unique “key” which together with the service EPR identifies the WS-resource pair.

37. Multiple services with a Factory Service
Use Resource Home to create resource
Request resource creation
Resource Home
Find resource
Service instance
Client
Manages
Methods operate on resources properties
Resource

38. Lifecycle Management
GT4 provides mechanisms to specify when a resource is destroyed:
Immediately by invoking destroy operation
Scheduled some time in the future
leased-based lifecycle management
Lease periodically renewed otherwise resource destroyed within a specified time.

39. Notifications
Informing clients to be notified when something interesting happens.
Example in assignment 2a

40. WS-Addressing A way of identifying a web service and resource
More versatile that using URIs
Address of a WS-resource pair is called an endpoint reference (EPR)
In assignment 2 example EPR just the service URL because single resource

41. WS-Addressing Terms
Endpoint – the destination where the web service can be accessed.
Endpoint reference, EPR –describes the destination, and includes the destination location as URI, but can have other parameters

42. Endpoint reference, EPR
Like all WS-* specs, defined in terms of XML.
Defined as complex type. Can contain:
Address (a URI) (required)
Reference Properties
Reference Parameters
Port type
Service name
Policy elements
Corresponds to portType and service of WSDL document

43. The minimum is simply the service address, using <wsa:Address> tag:
<wsa:EndpointReference>
<wsa:Address>
</wsa:Address>
</wsa:EndpointReference>

44. Reference Properties <wsa:ReferenceProperties> tag
Can be used to identify a resource properties in WSRF

45. WS-Addressing endpoint example
<wsa:EndpointReference>
<wsa:Address>
</wsa:Address>
<wsa:ReferenceProperties>
<resourceID>28</resourceID>
</wsa:ReferenceProperties>
</wsa:EndpointReference>

46. SOAP message WS-Addressing requires that contents of:
<wsa:Address>
<wsa:ReferenceProperties>
must appear in SOAP’s header.

47. Soap message
Address appears in <To> tag and ReferenceProperty in <resourceID> tag:
<soap:Envelop>
<soap:Header> .
<wsa:To>
<resourceID>28</resourceID>
</soap:Header>
<soap:Body>
</soap:Body>
</soap:Envelop>

48. Implied WS-Resource Pattern
Describes a specific relationship between a web service and a resource.
When a client accesses a web service with an implied WS-Resource pattern, the service returns a WS-addressing endpoint reference.

49. More Information GGF: http://www.ggf.org
GT4 services:
(Slides and assignment 2 based upon this tutorial)
GT4 tutorial by Foster:

50. Material in Books
The Grid 2: Blueprint for a new Computing Infrastructure, Ian Foster, Carl Kesselman and Steve Tuecker Editors, Morgan Kaufmann 2004
Chapter 17: “The Open Grid Service Architecture,” by Ian Foster, Carl Kesselman and Steve Tuecker.