Research on Exception Handling of Composite Services Based on Compensation Business Process Graph

Abstract

To enforce consistency and reliability of composite Web services at run-time, this paper proposes a novel approach based on compensation business process graph to addressing the problem of exception handling in composite services. According to compensation dependencies among tasks in business processes, the automatic generation of compensation business process graph is proposed. Compensation task, compensation goal and application model of service transfer are discussed in detail, and the relevant supporting infrastructure and technique are introduced. Based on this, algorithms for automatic generation of compensation dependency and compensation business process graph, as well as algorithm for exception handling during execution of composite services, are proposed. When exceptions are handled with forward- or backward-recovery methods during execution of composite services, the approach can guarantees compensation achieving, and also gives consideration to the problem that there are no compensation services or the cost to achieve compensation is too expensive. The mechanism described here improves self-adjustability and stability of composite services in the course of deployment and execution. Simulations prove that the approach can efficiently guarantee the consistency and reliability of composite services at run-time.