A flexible failure-recovery model for workflow management systems

In this paper, we propose a new failure-recovery model for workflow management systems (WfMSs). This model is supported with a new language, called the workflow failure-handling (WfFH) language, which allows the workflow designer to write programs so that he can use data-flow analysis technology to guide the failure recovery in workflow execution. With the WfFH language, the computation of the end compensation point and the compensation set for failure recovery can proceed during the workflow process run-time according to the execution results and status of workflow activities. Also, the failure-recovery definitions programmed with the WfFH language can be independent, thereby dramatically reducing the maintenance overhead of workflow processes. A prototype is built in a Java-based object-oriented workflow management system, called JOO-WfMS. We also report our experiences in constructing this prototype.