Interoperability Using Web Services

Web services naturally allow for interoperability, but at this point in time they don't do it perfectly and face a number of problems and challenges, which are being defined and addressed by the Web Services Interoperability Organization (WS-I). The WS-I organization provides developers with a framework in the form of Profiles, interoperability guidelines, test assertions and testing tools to test conformance of their Web services. A brief description of each follows:

• Profiles Profiles contain a list of named and versioned Web services specifications together with a set of implementation and interoperability guidelines recommending how the specifications should be used to develop interoperable Web services.

• Interoperability Guidelines In addition to references to specifications or standards, a Profile contains interoperability guidelines that resolve ambiguities or specify how to achieve consistent usage. This in turn increases the potential for interoperability of the implementations of the specification.

• Testing Tools Testing Tools are used to monitor and analyze interactions with a Web service to determine whether or not the messages exchanged conform to WS-I Profile guidelines.

  1. Monitor A tool used to intercept and log interactions with a Web service. This tool generates a log that is later processed by the Analyzer to verify that the monitored interactions conform to a Profile.

  2. Analyzer A tool used to process the logs generated by the Monitor to verify that the intercepted Web service interactions conform to the given Profile.

• Sample Applications Sample Applications demonstrate the implementation of applications that are built from Web services Usage Scenarios and Use Cases, and that conform to a given set of Profiles. Implementations of the same Sample Application on multiple platforms, using different languages and development tools, allow WS-I to demonstrate interoperability in action and to provide readily usable resources for the Web services practitioner.