Exception Diagnosis for Composite Service Based on Error Propagation Degree

Web services run in a highly dynamic environment (the Internet) which makes the composite service will face multiple exceptions in its execution. Thus, it needs to take effective actions to deal with the errors causing the exceptions. Then, by such actions, composite service can adapt to the dynamics and complexity of its execution environment. Since accurately identifying the error source which causes the exception is important, the problem of diagnosis for composite service becomes one of the key issues in the adaptive service composition. This paper proposes an approach for diagnosing composite service based on error propagation degree. After analyzing the error propagation relation between the services, the uncertain casual relation between the exception and the service is formed by the way of computing the error propagation degree. And then the diagnosis algorithm which is based on the error dependent matrix is established. The diagnosis can be achieved by fuzzy reasoning. This approach can preserve the efficiency and accuracy of the diagnosis for composite service under the uncertain environment by the computation of the error propagation degree and fuzzy reasoning, which can support the self-adaptation of the composite service effectively.