摘要
In previous researches in the field of supporting reliability and fault tolerance in web service composition, only low level programming constructs such as exception handling (for example in WSBPEL) were considered. However we believe 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 services 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.
In previous researches in the field of supporting reliability and fault tolerance in web service composition, only low level programming constructs such as exception handling (for example in WSBPEL) were considered. However we believe 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 services 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.