Research On Dynamic Evolution Technology Of Context-aware Web Service Composition

With the development of computer technology and Internet technology, service-oriented architecture is becoming a new architecture of distributed applications. As one of the means of achieving SOA, Web services and their composition are highly praised by the majority of vendors, organizations and research scholars. Especially with the development of sensor technology, everything on earth has become aware of each other and interoperable. Context-aware Web service composition is able to perceive the contexts and their changes of the user enviroment in real time, and then adjust the system behavior and provide services and computing resources for users proactively to reduce the human-computer interaction, improve the user experience and services pertinency. However, static Web service composition has been far from satisfying the needs of people because of the dynamic, open, changing and difficult controlled Internet environment. The ever-changing business environment also requires that the IT systems are able to rapidly adapt the changes of market demand and have the ability of dynamic evolution. It is with deep meaning that we combine the technologies of context-aware and dynamic evolution to research dynamic evolution model and methods of context-aware Web service in such environment.This paper proposes a dynamic evolution framework of context-aware Web service composition based on analyzing and summarizing the main framework of domestic and international dynamic evolution frameworks and deeply learning and researching the theory and technology of Web service composition, BPEL, context-aware, process algebra and dynamic evolution. The framework includes Web service container layer, Web service composition orchestration layer, context-awareness layer, strategy layer and evolution layer. It focuses on the dynamic evolution technology of context-aware Web service composition. This paper describes the dynamic evolution realization mechanism of context-aware Web service composition and the role of each functional module in the framework. This paper also provides an automatic mapping method from BPEL process of Web service composition to CCS process algebra description. Based on the CCS formal model of business process, behavioral consistency and behavioral compatibility of dynamic evolution of context-aware Web service composition are also verified. Finally, a case of E-guiding system is introduced to show the dynamic evolution process of context-aware Web service composition. And the dynamic evolution features of this system are verified with the behavioral consistency and behavioral compatibility verification mechanism proposed in this paper.