Research On Web Service Compatibility And Substitutability Base On Behavior

In recent years, as the rapid development of Internet technology and Web applications, distributed computing model based on Web services is becoming the new trend of technological development. Web service is a web-based, distributed, self-describing, modular component, which according to certain specifications, achieves specific functions, and provides a unified, registration, discovery, binding, and integration mechanism service-oriented Internet applications. The Web service composition enables multiple services cooperation and coordination work, thus achieving more complex functions. So it becomes a primary mechanism to implement interoperability in wide-area environment.Web service composition is most important research direction of Web services. In order to ensure multiple services can work coordinated to achieve specific functions, it needs the behavior of each service which participates service composition to satisfy certain conditions. So as to ensure the service compatibility. On the other side, to ensure the flexibility of service composition. We need to consider the service substitutability. In other words, when we use a new service to substitute the one involved in service composition, it doesn't occur incompatible relationship.In this paper, we proposed the standards to determine the compatibility of two Web services when they work together. And designed a formal determination methods based on process algebra and automata, and then illustrated it with examples. On the other hand, we extracted the necessary and sufficient conditions for one new service to substitute another service which participated in service composition based on the requirement of services substitutability, and proved it. Under those conditions, we got some useful inferences which can be used to simply determine services substitut-ability. Finally we discuss the relationship between services compatibility and service substitutability.