Research On Transaction Mechanism For Web Service Asynchronized

In recent years, the rapid development of Internet technology makes the Web service gradually cover all aspects of people's life. For the Web service combination and for users, they all need to interact with each other to finish the whole business process. In practice, the industry use synchronous communication mechanism to handle message interaction problems between business process participants, however, due to the problems such as waiting and blocking in the synchronous communication, the reliability and efficiency of service can not be guaranteed. Asynchronous Web services are obviously better than synchronous Web services in reliability, performance and flexibility. At the same time, with the popularity of asynchronous Web services, the correct interaction of participants in the long cycle of the business process and consistency of the results are vital. In view of the above problem, this thesis presents a timed automata based transform algorithm that makes synchronous Web services transform to asynchronous Web services, and modeling the participants and coordinator in asynchronous Web services coordination, the coordination strategy and exception handling methods are given. The major work is listed as follows:Firstly, analyzed the asynchronous demand of Web services and the time constraints that may exist in the process of Web services interaction, and then proposed the timed automata based model of Web service, based on this the transformation rules of WS-BPEL to timed automata is given, finally gives the judge condition of asynchronous and the design of asynchronous algorithm.Secondly, analyzed the transaction mechanism demand for asynchronous Web service, then modeling the participants and coordinator in the process of asynchronous Web services transaction coordination, and presents a coordinate algorithm and coordination strategy, finally studied the recovery strategy for the constraint.Thirdly, designed and implemented the Web services transaction system using the proposed method, the system will analyzed and returned the asynchronously executed interaction; for users,services that satisfy their needs is recommended. Finally, an example is given to illustrate the feasibility and effectiveness of this method.