A workflow-based failure recovery in web services composition

In previous researches in the field of supporting reliability and fault tolerance in web service composition, only low le-vel programming constructs such as exception handling (for example in WSBPEL) were considered. However we be-lieve that the reliability and fault tolerance for composite services must be handled at a higher level of abstraction, i.e. at the workflow level. Therefore a language and technology independent method for fault-tolerant composition of web ser-vices is needed. To do this, a fault tolerant workflow is built in which the execution order of the services is determined such that upon a service failure a recovery process with the lowest cost is started. The cost of a service failure includes the cost of failed service and the total costs of roll-baking the previously executed services which are dependent on the failed service. In this article a FSP language is applied to formally specify the workflow