Method, system, and web service broker for dynamic web service invocation

• US 20060265720A1
• Filed: 05/22/2006
• Published: 11/23/2006
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cai, Jun Jie, Tong, Chun Jie
• Granted Patent: US 7,529,833 B2
• Time in Patent Office: Days
• US Class Current: 719/330
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A method, system and Web service broker with requester'"'"'s explicit control for dynamic Web service invocation. In accordance with the method a Web service request is constructed by a Web service requester, in which invocation criteria customized by the requester are included and the Web service request is sent to a Web service broker. The Web service broker discovers and invokes Web service implementation candidates that meet the invocation criteria based on the Web service request and returns the best invocation result as well as a session identifier for identifying this service request to the requester. The requester can explicitly control the process of Web service invocations through customized Web service requests, thus delegating the whole invocation process to a Web services broker to reduce the complexity of client-side tasks. In addition, the Web service invocation allows a series of invocations with a consistent business sense to be directed to the same Web service interface.

Claims

1. A method for dynamic Web service invocation at a service broker, comprising:

receiving a Web service request from a Web service requester, said request comprising invocation criteria customized by the requester;

discovering and invoking Web service implementation candidates that meet the invocation criteria based on the Web service request; and

returning the best invocation result as well as a session identifier for identifying the service request to the requester.

2. The method as claimed in claim 1, wherein said invocation criteria customized by said requester include service discovery rules, and wherein said discovering comprises guiding a corresponding discovery mechanism to discover Web service implementation candidates that meet the service discovery rules.

3. The method as claimed in claim 2, wherein said discovery mechanism is one of UDDI, WSIL and USML.

4. The method as claimed in claim 1, wherein said invocation criteria customized by the requester further include service selection rules, and wherein said method further comprises identifying selected Web service implementation candidates that meet the service selection rules from the discovered Web service implementation candidates.

5. The method as claimed in claim 1, wherein said invocation criteria customized by the requester comprises invocation result comparison rules and wherein said method further comprises:

determining if said Web service invocation is a follow-up invocation containing a session identifier for identifying the previous service request; and

if said Web service invocation is a follow-up invocation,

invoking the Web service implementation candidates;

finding the best Web service implementations in accordance with the invocation result comparison rules; and

returning the best invocation result as well as the session identifier for identifying the service request to the requester.

6. The method as claimed in claim 5, wherein said invocation result comparison rules are related to a manner for expressing said invocation results.

7. The method as claimed in claim 6, wherein, if said invocation results are expressed in Extensible Markup Language, said invocation result comparison rules include:

value locators, comparators and optional constant objects.

8. The method as claimed in claim 1, wherein said service broker invokes various Web service implementation candidates in parallel.

9. The method as claimed in claim 1, wherein said invocation criteria in the Web service request is customized by said Web service requester in Web Service Hyper Search Language.

10. The method as claimed in claim 9, wherein said invocation criteria customized by the Web service requester in Web Service Hyper Search Language are embedded in the header of a SOAP message.

11. A Web service broker for implementing dynamic Web service invocations, comprising:

a control module for controlling operations of components in a service broker according to customized invocation criteria contained in a Web service request received at said service broker from a Web service requester;

a discovery module for discovering Web service implementation candidates that meet said invocation criteria from a source of Web service implementations;

a selection module for further selecting Web service implementation candidates that meet said invocation criteria from the Web service implementation candidates discovered by said discovery module according to said invocation criteria; and

an invocation and comparison module for invoking each one of said Web service implementation candidates and comparing invocation results returned by the Web service implementation candidates according to said invocation criteria, so as to select the best Web service implementations.

12. The Web service broker as claimed in claim 11, wherein said control module further comprises:

a route service module for receiving a Web service request from a Web service requester and returning response messages of the service broker to the requester;

a Web service request parser for parsing the Web service request from the route service module and extracting various rules for the discovery module, selection module or invocation and comparison module, respectively;

a session manager for maintaining session information, wherein the session information contains correspondence relation between a session identifier for identifying a service request and the service implementation candidates obtained during the session indicated by the session identifier; and

a response handler for constructing a service response message based on the processing results by said discovery module, selection module or invocation and comparison module and sending the message to the requester through said route service module.

13. The service broker as claimed in claim 11, wherein said invocation criteria contain at least one of one or more service discovery rules, one or more service selection rules, and one or more invocation result comparison rules.

14. The Web service broker as claimed in claim 13, wherein said discovery module further comprises:

a discovery executor for parsing said one or more service discovery rules, and for each service discovery rule invoking a corresponding discoverer module in a discoverer container for enforcing the rules, and obtaining Web service implementation candidates that meet said invocation criteria based on the results of enforcing the various service discovery rules; and

a discoverer container that contains one or more discoverer modules, each of which implements a discovery mechanism for discovering Web service implementation candidates that match the service discovery rule.

15. The Web service broker as claimed in claim 14, wherein said discovery mechanism is one of UDDI, WSIL and USML.

16. The Web service broker as claimed in claim 13, wherein said selection module further comprises:

a selection executor for parsing said one or more service selection rules, and for each service selection rule invoking a corresponding selector module in a selector container for enforcing the rules, and selecting Web service implementation candidates that meet said invocation criteria based on results of enforcing the various service selection rules; and

a selector container that contains one or more selector modules, each of which is used to select selected Web service implementation candidates that match a service selection rule from discovered Web service implementation candidates discovered by the discovery module.

17. The Web service broker as claimed in claim 13, wherein said invocation and comparison module further comprises:

an invoker that invokes each of said Web service implementation candidates;

a comparison executor for parsing said one or more invocation result comparison rules, and for each invocation result comparison rule invoking a corresponding comparator module in comparator container for enforcing the rule, and obtaining the best Web service implementations that meet said invocation criteria based on the enforcing results of the various invocation result comparison rules; and

a comparator container that contains one or more comparator modules, each of which is used to compare invocation results of various Web service implementation candidates returned from said invoker and select the best Web service implementations that match the invocation result comparison rule.

18. The Web service broker as claimed in claim 17, wherein said invoker invokes each of said Web service implementation candidates in parallel.

19. The Web service broker as claimed in claim 17 wherein if said invocation results are expressed in Extensible Markup Language, said invocation result comparison rules include:

value locators, comparison operators and optional constant objects.

20. A dynamic Web service invocation system, comprising a Web service broker for implementing dynamic Web service invocations, said Web service broker comprising:

a control module for controlling operations of components in a service broker according to customized invocation criteria contained in a Web service request received at said service broker from a Web service requester;

a discovery module for discovering Web service implementation candidates that meet said invocation criteria from a source of Web service implementations;

a selection module for further selecting Web service implementation candidates that meet said invocation criteria from the Web service implementation candidates discovered by said discovery module according to said invocation criteria; and

an invocation and comparison module for invoking each one of said Web service implementation candidates and comparing invocation results returned by the Web service implementation candidates according to said invocation criteria, so as to select the best Web service implementations.