基于拓扑序列归约的Web服务组合QoS度量算法  

QoS computing method for Web services composition based on topological sequence reduction

作　　者：李兴芳[1] 苑迎春[1,2] 王克俭[1] 

机构地区：[1]河北农业大学信息科学与技术学院,河北保定071001 [2]河北省农村信息化工程技术研究中心,河北廊坊065000

出　　处：《计算机应用》2012年第5期1432-1435,共4页journal of Computer Applications

基　　金：国家自然科学基金资助项目(60873236);河北省自然科学基金资助项目(F2009000653);河北省教育厅科学研究项目(2010251)

摘　　要：考虑有向无环图(DAG)描述的组合服务模型,提出了一种新的组合服务QoS度量方法———基于拓扑序列归约的Web服务QoS度量方法(QCMTSR)。其借鉴迭代归约度量方法中的基本结构及QoS计算公式,定义了DAG图中的两类基本结构,串归约结构和并归约结构,并给出了两种基本结构的QoS属性计算公式;通过逐步归约DAG图拓扑序列中的每个节点,直至最后一个节点的QoS属性值就是组合服务的各QoS属性的度量结果。从理论上证明了QCMTSR算法适用于所有DAG描述的组合服务,并实验证明QCMTSR算法对可靠性和可用性能够更准确的度量。In this paper, considering the Web service composition model described by DAG （ Directed Acrylic Graph）, a new Quality of Service （QoS） computing method for the composition service based on topological sequence reduction （QCMTSR） was proposed. Based on the basic structures and their QoS computing formulas of iterative reduction method two kinds of basic structures （ i. e. serial reduction structure and parallel reduction structure） were defined in graph DAG, and their QoS calculation formulas were also given. During accessing each node step by step in the topology sequence for DAG. Repeating this process until the last node in this queue, then the QoS measure results of the last node were the computing results of the composition service. It has been proved that the algorithm can be applied to all the composition services described by DAG, and the experimental results show that the algorithm QCMTSR is more accurate in the measurement of reliabilit~ and availability.

关 键 词：WEB服务组合 QOS度量 有向无环图 拓扑序列归约 面向服务架构 

分 类 号：TP311.5[自动化与计算机技术—计算机软件与理论] TP302.7[自动化与计算机技术—计算机科学与技术]