FIRMS TUTORIAL Leveraging WSRM and WSR

FIRMS TUTORIAL Leveraging WSRM and WSR Community Grids Lab, Indiana University 1 FIRMS Tutorial: Outline Some Observations about WS-* specifications WS-Addressing Reliable Messaging Overview WS-Reliable Messaging WS-Reliability Deploying FIRMS Running FIRMS within the OMII Container FIRMS-Tutorial 2Part I – S ome Observations about WS-* specifications FIRMS-Tutorial 3 Some quick observations about WS-* Typically addresses core areas or those where the demand is substantial enough to eschew proprietary ad hoc solutions. In some cases common issues across various WS-* specifications mandate additional WS-* specifications. Exemplars include WS-Addressing, WS-Policy. Various specifications are intended to incrementally augment capabilities at an endpoint. For e.g. if you need reliable messaging capabilities simply plug in a WSRM or WSR module. If you need notification capability plug in WS-Eventing o r WS-Notification. FIRMS-Tutorial 4 Some quick observations about WS-* Functionality of specifications encapsulated within stand-alone SOAP messages. They typically also include a WSDL definitions of operations, but all functionality is encapsulated in SOAP messages. Primary interaction model is one-way, asynchronous SOAP messaging. Lot of these specifications are also intended to be stackable. FIRMS-Tutorial 5XML Schema WS- * SOA P R u les WS- E v e n t in g WS-A ddressing WS- R M WS- P o l icy WS-Securit y FIRMS-Tutorial 6 Typical implementation strategy Develop strategy for processing the XML Schema associated with the specification. This would allow you to process the XML messages from Java (or language of choice). XML generated over the wire should be conformant to the relevant schemas . This allows one to interact with other implementations. Develop Processor to enforce rules and processing associated with the specification. This would include performing actions, issuing requests/responses and faul t s . Ensure that rules and processing related to leveraged specifications are enforced. FIRMS-Tutorial 7 Processing XML Schemas We were looking for a solution that allowed us to process XML from within the Java domain. There are 4 choices Develop Java classes ourselves Use wsdl2java to do this Use the JAXB Data Binding Framework Use a schema compiler such as Castor or XMLBeans FIRMS-Tutorial 8 Writing one’s own classes Approach used by Apache’s Sandesha project. Implementation of WSRM Error prone and quite difficult Increasingly the developer has to deal with several other specifications. Another approach is to just process messages based on DOM. Quite difficult to do. No examples that we are currently aware of. FIRMS-Tutorial 9 WSDL2Java Problems Issues (in version 1.2) related to this tool’s support for schemas have been documented in http://www- 106.ibm.com/developerworks/webservices/library/ ws-castor/ . Specifically, the problems relate to insufficient (and in some cases incorrect) support for complex schema types, XML validation and serialization issues. FIRMS-Tutorial 10