基于策略的Web服务实时性能评价与验证

Policy-Based Runtime Performance Evaluation and Validation of Web Services

面向服务的架构（SOA）通过标准Internet协议实现了异构平台上的服务动态集成.然而,开放网络环境的不稳定性和不确定性,给Web服务在线质量评价带来一定的困难.Web服务的测试只能给出测试环境下的服务评价,不能评价服务的真实运行情况,因此服务实时监测对服务运行状态追踪及异常检测具有重要的意义.本文基于服务系统的协同监测,采用原子服务和组合服务多种时间特性定义了Web服务的性能评价模型.在该模型的基础上,提出了一种基于策略的服务在线质量评价与验证方法,给出了基于WSPolicy的策略描述,实现了原型系统,并通过对实验服务的在线监测数据,分析了方法的有效性及性能代价.

Service-Oriented Architecture （SOA） enables the dynamic composition of services across heterogeneous platforms through standard Intemet protocols. However, it is hard to evaluate service runtime qualities due to the instability and uncertainty of the open Intemet environment. Testing is usually exercised in the dedicated testing environment and cannot analyze service behavior in the execution environment. Hence,runtime monitoring is necessary for runtirne system status tracking and anomaly detection. The paper is an extension of our previous research on the collaborative monitoring of service-based systems. It defines a service perfor- mance evaluation model using the temporal properties of both atomic and composite service executions.Policies are defined and en- coded following the WS-Policy framework. They are enforced at runfirne for evaluating the service performance based on the evalua- tion model. A prototype system is implemented. Experiments are exercised to illustrate the proposed approach and analyze the moni- toring overhead.