The Research And Implementation Of Exception Handling Of Composite Services Based On Autonomic Management

Web service is a booming distributed computing technology that enables cross-platform, cross-programming language interoperability in recent years. More and more companies release their applications as Web services, but with the increasing complexity of cross-enterprise applications, a single service is increasingly difficult to meet the practical requirements. We need composite a number of different Web services according to certain business processes to build a complex composite service. With the execution of the composite service, it can meet the requirement of the complex business logic.BPEL has become the de facto standard for service composition description language, it can composite the services distributed on the network in accordance with the specific business logic to form a composite services of a service-oriented processes. However, because of the inherent loosely coupled, dynamic runtime environment complexity and the lack of strong exception-handling mechanism of BPEL process, how to ensure the stability and reliability of the execution of composition service process is a problem that must be solved.The background of this paper is exception handling of composite services and made a thorough research of existing composite service exception handling techniques. This paper proposed an effective exception handling model of composite Web services in combination of the autonomic management theories and techniques in the field of autonomic computing. This paper focuses on the mechanism of exception handling based on autonomic management by introducing the basic elements of autonomic computing. The basic process is if the BPEL process occurs an exception, it wills performe exception handling activities defined in the process. In fact, this activity just invoke a monitoring service (Equivalent to the monitoring part of the autonomic elements).Then the specific type of exception will be given through a diagnosis (Equivalent to the analyze part of the autonomic elements).and then select a policy according on the exception (Equivalent to the plan part of the autonomic elements), and finally execute the selected policy to achieve the purpose of the exception handling (Equivalent to the execute part of the autonomic elements). The core of this model is the exception autonomic management section, and the exception handling of this section reduces the exception processing complexity of BPEL process. The final system proves that this model enhances the exception handling autonomy while reducing the complexity of exception handling of composite service.