【作者】 李俊宝；

【导师】 刘振鹏；

【作者基本信息】 河北大学 ， 计算机应用技术， 2010， 硕士

【摘要】 Web服务基于XML、SOAP、WSDL、UDDI等技术标准,是一种自我包含、自我描述的模块化应用,它实现平台、编程语言无关性,很好地解决异构平台上应用整合与数据共享问题。随着Web服务技术快速发展以及该技术应用的日趋深入,服务使用者对于Web服务功能和QoS要求逐步提高,服务提供者也期望通过提供Web服务获得更多的收益。语义Web服务技术的发展为实现基于QoS的Web服务发现、选择以及组合提供了技术基础。然而,在Web服务体系结构的商业应用中,要实现保障QoS和服务提供者获益的目标,还存在多方面的关键技术需要进行研究。例如:Web服务的QoS信息通常是由服务提供者提供,QoS信息客观真实性难以保证;Web服务QoS管理通常采用计算最终QoS值的方法,这种方法不能反映QoS未来变化趋势;在Web服务的QoS反馈评价数据中存在由于主观故意或客观因素造成的不准确QoS评价数据;如何建立保障QoS和最大化服务提供者获益的机制。本文对上述几个方面关键技术展开研究,给出基于QoS与服务提供者获益的Web服务组合模型。该模型实现Web服务QoS趋势评估算法和基于Web服务QoS趋势的QoS评价误差消除算法,应用这两个算法提高Web服务QoS反馈评估的准确性;实现基于QoS的Web服务发现、选取和组合,确保所形成服务组合方案的有效性,实现分布调用不同服务提供者服务器上的相同功能Web服务;采用最大化服务提供者获益的服务调度算法,保障服务提供者获益。更多还原

【Abstract】 Web Services technology is based on some technical standards such as XML, SOAP, WSDL and UDDI. It is a self-contained, self-describing, modular technology. It realizes the platform independence and the programming language independence, thus it solves some technical problems such as application integration and data sharing in heterogeneous platforms. With the rapid development of Web Services technology, this technology has been widely used. The users of Web Services require better QoS and the providers of Web Services expect more benefit by providing Web services.The development of Semantic Web Services technology provides a technical basis for QoS-based Web Services discovery, selection and composition. However in order to ensure QoS and service providers’benefit in SOA applications in business domains, there are some key technologies need to be studied. Under normal circumstances the information of QoS is provided by Web services provider, thus it is difficult to guarantee the objectivity of the QoS information. In existing QoS management studies, the final QoS value is computed to reflect the general QoS of a Web service. Such a single final QoS value cannot reflect QoS trend. Usually there are some inaccurate feedback evaluation data of QoS cased by subjective or objective factors. How to guarantee QoS and maximize the providers’benefit is also a problem.To deal with the problems above-mentioned a model for Web Services composition based on QoS and providers’benefit is studied. An algorithm for QoS trend evaluation and an algorithm to eliminate the errors in QoS feedback evaluation data are realized in this model. The two algorithms are adopted to enhance the veracity of QoS evaluation. This model realizes QoS-based Web Services discovery, selection and composition, guarantees the availability of Web Services composition. The Web Services request scheduling algorithm in this model maximizes service providers’benefit.更多还原