Web服务器群的QoS确保及其接纳控制研究

Research on Ensuring QoS and Its Admission Control in Web Servers

WWW访问的爆炸性发展正是Internet成功的重要原因,然而目前的Web服务器却缺乏相应的QoS机制,导致在过载时造成巨大的经济损失.一个提供多类服务的多服务器Web平台的服务质量确保体系被提出来,它以服务响应延迟为核心度量标准,将同一类服务抽象为一台虚拟服务器,并以该度量黏合起系统的各个组件.同时据此提出了一个动态自适应的服务接纳算法(DASAC).测试表明,即使经历严重的过载与业务突发,也能保证用户感知的服务质量.

The explosive growth in WWW is the main cause of Internet success. But because the current Web servers architecture is short of QoS ensuring mechanism, it leads to significant revenue losses while server is overloaded. A QoS ensuring architecture for Web servers which provide multi-class service is presented in this paper. It uses (SRD) service response delay as the core measurement criterion of the architecture. With SRD, one class service is abstracted to a virtual server, and every component of a system are glued together. And a dynamic adaptive service admission control algorithm (DASAC) is also presented. Experiments show that, although suffering severe overloading and burst, the user-perceived QoS can be ensured.