With the development of Web service technology, using composite services to satisfy users' requirements has become an inevitable tendency. Goal changes caused by changing requirements of users may directly drive t...With the development of Web service technology, using composite services to satisfy users' requirements has become an inevitable tendency. Goal changes caused by changing requirements of users may directly drive the corresponding evolution of service composition. However, most researches focus on how to compose services, and little efforts have been placed on how to evolve the composite services with changing requirements. In this paper, the service composition patterns are defined based on workflow patterns, and the changes of service composition patterns are analyzed according to changing goals. Finally, a case study is given to demonstrate the feasibility of the proposed approach.展开更多
Providing reliable compositions of Web Services is a challenging issue since the workflow architect often has only a limited control over the reliability of the composed services. The architect can instead achieve rel...Providing reliable compositions of Web Services is a challenging issue since the workflow architect often has only a limited control over the reliability of the composed services. The architect can instead achieve reliability by properly planning the workflow architecture. To this end he must be able to evaluate and compare the reliability of multiple architectural solutions. In this paper we present a useful tool which allows to conduct reliability analysis on planned workflows, as well as to compare the reliability of alternative solutions in a what-if analysis. The tool is implemented as a plug-in for the widely adopted Active BPEL Designer and exploits the concept of reliability pattern to evaluate the reliability formula of the workflow. The effectiveness of the approach and the operation of the tool are demonstrated with respect to a case study of a business security infrastructure realized by orchestrating simple security services.展开更多
基金National Natural Science Foundation of China (No. 60970017 )Fundamental Research Funds for the Central Universities,China (No. 3101034,No. 6082008,No. 201121102020004)
文摘With the development of Web service technology, using composite services to satisfy users' requirements has become an inevitable tendency. Goal changes caused by changing requirements of users may directly drive the corresponding evolution of service composition. However, most researches focus on how to compose services, and little efforts have been placed on how to evolve the composite services with changing requirements. In this paper, the service composition patterns are defined based on workflow patterns, and the changes of service composition patterns are analyzed according to changing goals. Finally, a case study is given to demonstrate the feasibility of the proposed approach.
文摘Providing reliable compositions of Web Services is a challenging issue since the workflow architect often has only a limited control over the reliability of the composed services. The architect can instead achieve reliability by properly planning the workflow architecture. To this end he must be able to evaluate and compare the reliability of multiple architectural solutions. In this paper we present a useful tool which allows to conduct reliability analysis on planned workflows, as well as to compare the reliability of alternative solutions in a what-if analysis. The tool is implemented as a plug-in for the widely adopted Active BPEL Designer and exploits the concept of reliability pattern to evaluate the reliability formula of the workflow. The effectiveness of the approach and the operation of the tool are demonstrated with respect to a case study of a business security infrastructure realized by orchestrating simple security services.
