Methods for Enabling Recovery Actions in Ws-BPEL

Self-Healing is an emerging exigency for Information Systems where processes are everyday more complicated and where many autonomous actors are involved. Roughly, self-healing mechanisms can be viewed as a set of automatic recovery actions fired at run-time according to the detected fault. These actions can be at infrastructure level, i.e. transparently to the process, or they can be defined in the workflow model and executed by the workflow engine. In the Service Oriented Computing world Ws-BPEL is the most used language for web-service orchestration, but standard recovery mechanisms provided by Ws-BPEL are not enough to implement, with reasonable effort, lots of suitable recovery actions.

This paper presents an approach where a designer defines a Ws-BPEL process annotated with some information about recovery actions and then a preprocessing phase, starting from this “annotated”Ws-BPEL, generates a “standard” Ws-BPEL, that is a file understandable for a standard Ws-BPEL engine. This approach has the advantage of avoiding any change in the engine using the standard capabilities to define specific behaviors that will realize recovery actions, but at the end are still a set of Ws-BPEL basic and structured activities.