Abstract:

To solve the problem of large amount of calculation and nonlinear programming in the process of service composition optimization, a Cost Benefit Coefficient (CBC) approach was proposed for Web services composition reliability optimization in the situation of a given cost investment. First, the structure patterns of service composition and related reliability function were analyzed. Furthermore, the Web service composition method of reliability calculation was proposed and a nonlinear optimization model was established accordingly. And then the cost benefit coefficient was computed through the relationship between the cost and the reliability of component services, and the optimization schemes of Web service composition were decided. According to the nonlinear optimization model, the results of optimization were computed. Finally, given cost investment, the higher reliability of the approach to optimize the reliability of Web service composition was verified through the comparison of this approach and the traditional method on the reliable data of component service. The experimental results show that the proposed algorithm is effective and reasonable for reliability optimization of Web services composition.

Key words: Web service composition, Quality of Service (QoS), cost benefit coefficient, probability, optimal model

摘要：

为了解决Web服务组合优化过程计算量大、非线性等问题，提出在给定成本约束下利用成本效益系数(CBC)对Web服务组合可靠性进行优化的方法。首先分析了Web服务组合结构模式及其对应的可靠性函数，进一步给出服务组合的可靠性计算方法，并建立非线性可靠性优化模型；然后，通过组件服务的成本及其可靠性关系计算成本效益系数，进一步确定Web服务组合的优化方案，再根据优化模型计算得到优化结果；最后，以组件服务可靠性数据为基础，通过与传统的优化方法比较，验证了基于成本效益系数的方法可以在给定成本约束时获得更高的可靠性。实验结果表明，所提方法对Web服务组合进行可靠性优化是有效、合理的。

关键词: Web服务组合, 服务质量, 成本效益系数, 可靠性, 优化模型