Enabling Robustness in Existing BPEL Processes

Web services are increasingly being used to expose applications over the Internet. To promote efficiency and the reuse of software, these Web services are being integrated both within enterprises and across enterprises, creating higher function services. BPEL is a workflow language that can be used to facilitate this integration. Unfortunately, the autonomous nature of Web services leaves BPEL processes susceptible to the failures of their constituent services. In this paper, we present a systematic approach to making existing BPEL processes more fault tolerant by monitoring the involved Web services at runtime, and by replacing delinquent Web services. To show the feasibility of our approach, we developed a prototype implementation that generates more robust BPEL processes from existing ones automatically. The use of the prototype is demonstrated using an existing Loan Approval BPEL process.