【摘要】 如何动态地选择、绑定并调用最适合用户需求的Web服务备受研究领域的关注.提出了一种QoS有保障的Web服务分布式发现模型,具体研究基于QoS约束的服务发现问题,以及如何提高服务发现系统的可用性问题.研究Web服务的三维QoS模型并设计基于QoS约束的服务选择算法.提出集成服务选择算法的UDDI(universal description,discovery,andintegration)兼容扩展模型,并运用可扩展Kautz图和Bloom Filters理论,提出分布式UDDI的实现机制.该模型的原型系统在国家地质调查网格中得到应用,测试结果显示:扩展UDDI模型具有很高的查准率、响应率以及较好的负载均衡能力,而模型的分布式实现机制在保障查询性能的前提下,提高了发现系统的有效性和可用性.更多还原

【Abstract】 How to dynamically select,bind and invoke Web service that can best meet the requirements of service consumer is an ongoing research topic in Web services community.In this paper,a QoS-Guaranteed and distributed mechanism of Web service discovery is proposed,which supports Web service discovery with QoS constraints and enhances the QoS of service discovery system.First,a novel three-dimensional QoS model of Web service is introduced,and a Web service-selecting algorithm is proposed based on the novel model.Second,the implementation model of UDDI(universal description,discovery,and integration)specification is improved by integrating the service-selecting algorithm based on QoS constraints.Third,an unstructured peer-to-peer network of UDDI with an informed routing protocol based on Bloom Filters is proposed,and an extended Kautz graph is used as the logical topology of this network.The experimental results show that the new mechanism for Web service discovery possesses higher recall rate,query response rate,and better load balance.Furthermore,the results for QoS of the selected Web service can satisfy the requirements of service consumers.更多还原