Using WS-BPEL to Implement Software Fault Tolerance for Web Services

One area of the Web services architecture yet to be standardised is that of fault tolerance for services. At the same time, WS-BPEL is moving from a de facto standard to an OASIS ratified standard for combining services into processes. This paper investigates the feasibility of using WS-BPEL as an implementation technique for fault tolerant Web services. The mapping of various fault tolerance patterns to WS-BPEL is presented. A prototype tool for combining service interfaces into a single facade and configuring fault tolerant mechanisms on a per-operation basis is also discussed. It is found that most fault tolerance patterns readily map onto WS-BPEL concepts, particularly when using the upcoming 2.0 version of the language. Evaluating and minimising the performance overheads involved in process execution is identified as a key future direction, as is working on the functionality and usability of the configuration tool