网格环境下多服务质量约束的复合服务调度机制

Scheduling mechanism of composite grid service with multiple QoS constraints

目前,由于没有一个动态、可扩展的服务组合模型,在服务网格环境中缺乏满足多性能目标约束的、复合服务的调度机制。为此,在分析动态服务调度机制基础上,将服务质量约束引入到状态图工作流模型中,提出一种多服务质量约束的动态组合服务模型,给出了在服务组合过程中保持服务组件之间服务质量一致性的方法,并将复合服务的调度问题(即执行路径的动态选择问题)归结为多属性决策问题。采用简单加权法,以保证组合后的服务满足综合服务质量约束。通过实现的服务调度组件验证了该机制的可行性和有效性。

To deal with the problem of scheduling service with multiple QoS constraints in service grid, based on analysis of dynamic services scheduling mechanism, with introduction of Quality of Service （QOS） constraints to state--chart based workflow model, a model of service composition with multiple QoS constraints was presented and a method to keep QoS consistency during the process of service composition was proposed. Then, a scheduling service component was implemented by evolving the scheduling problem of executing path of composite service to the problem of Multiple Attribute Decision Making （MADM） which could be solved by using Simple Additive Weight （SAW） method. The result indicated that the proposed mechanism was feasible and efficient on scheduling dynamic composite services in service grid.