Failure-Recovery-Strategies-Based QoS Estimation for Web Composition Transaction

To assure its transactional properties, composite Web service based applications require more transactional supports than traditional transactions, which has inevitably led to the need for appropriate failure recovery mechanisms that can provide sustainable and reliable execution semantics. In this paper, a comprehensive transaction recovery model is proposed, which includes forward recovery, backward recovery and alternative recovery. Failure recovery strategies are separated from business flow to dynamically model and program the failure recovery. With respect to the advanced aggregation patterns, since failed task will affect execution proceeding of Web composition transaction, and the existing QoS evaluation methods do not consider failure recovery, it can not be used directly in QoS estimation of Web composition transaction. According to the situations of both correct and failed, a QoS estimation model based on the performance of composition transactions is proposed. The results show that the proposed model can evaluate and analyze the performance of composition transactions effectively, reduce the failure rate of composition transaction, and eliminate the bad effects efficiently.