The Study Of Conversation Model And Conversation Manager For Web Services

Web services are emerging as a promising technology for the effective automation of inter-organizational interactions. Several standards that aim at providing infrastructure to support Web services description, discovery, and composition have recently emerged including WSDL, UDDI, and BPEL4WS. Indeed, advances in this area promise to take cross-organizational application integration a step further by facilitating the automatic discovery and invocation of relevant services. However, despite the growing interest in Web services, several issues still need to be addressed to provide similar benefits to what traditional middleware brings to intra-organizational application integration (e.g., transaction support).The exploitation of Web Services in e-commerce applications is affected by their limited support to the interaction with the peers requesting their services. The emerging standards for the publication of Web Services enable the invocation of services having simple interaction protocols, but they fail to support complex e-business interactions, where the peers exchange several messages.In order to extend the communication capability of Web Services, and to extend the classes of services which can be invoked by the consumers, we propose a conversational model supporting the management of complex interactions between clients and Web Services, where several messages have to be exchanged before the service is completed. Our model supports the consumer in the management of a conversation which respects the business logic of the service without imposing the explicit management of the conversational context. The proposed model is based on the exploitation of current emerging standards for Web Services. Finally, we show how the model are supported by a conversation manager implemented on top of the SELF-SERV platform.