SOAP over JMS support for the Stuttgarter workflow machine

Abstract

Web services constitute the function layer of the two-level programming model that is characteristic for workflow-based applications in a heterogeneous and distributed environment. The model involves two parts. First descriptions of business process models defining the sequence and activities that are carried out during the execution of the business processes (programming in the large). Second the individual components implementing the various activities (programming in the small). The Stuttgarter Workflow Machine (SWoM) is a workflow management system (WFMS) implementing partially the WS-BPEL standard for the business process model description. The purpose of the system is to manage the life cycle of business processes, to navigate through the associated process models and invoke the appropriate web services implementing activities. The purpose of this diploma thesis was to architect, design and implement enhancements for the Stuttgarter Workflow machine to support the Simple Object Access Protocol (SOAP) with the Java Message Service (JMS) as underlying transport alternative to the Hyper Text Transfer Protocol (HTTP). The document describes and illustrates the necessary tasks enabling the participating web services to exchange messages via persistent message queuing providing more reliability and robustness for the transmission of business data. The work covers the creation and administration of the necessary Java Messaging Service (JMS) resources. Furthermore the automated generation of components in particular message-driven beans performing the message consumption and components for the invocation of partner web services via JMS messages. The approach used for the implementation includes distinct queues for each process model for scalability. A main focus is on the end to end message dispatching from individual web services participating in a business process instance to another. As a result it is shown that it is possible to deploy process model descriptions in WS-BPEL and generated components on WebSphere as application server automatically allowing the Stuttgarter Workflow Machine to rely on the Java Message Service as message oriented middleware (MOM).