异构Web集群中的比例伸展因子区分服务  

Proportional Stretch Factor Differentiated Service in Heterogeneous Web Server Cluster

作　　者：熊智[1] 晏蒲柳[1] 郭成城[1] 

机构地区：[1]武汉大学电子信息学院,武汉430079

出　　处：《计算机科学》2006年第10期61-65,共5页Computer Science

基　　金：国家自然科学基金(90204008);武汉市重大科技攻关项目(20001001004)的资助。

摘　　要：Web集群服务器已被广泛用来提高Web服务器的性能。如何保证Web服务的服务质量(QoS)是一个迫切需要解决的问题。区分服务已成为QoS研究领域中的一个焦点。本文分析了Web请求服务时间的数字特性,并使用M/G/1FCFS排队模型对Web服务器及Web集群服务器进行了建模。在对模型进行分析的基础上,设计并实现了一种异构Web集群服务器中的比例伸展因子区分服务的方案,并提出了基于概率空间的请求调度算法。请求被分成多个类,无论系统的负载如何,系统确保每类请求的平均伸展因子与事先给定的参数成正比。实际测试表明,所设计的方案满足相对区分服务的可预测性和可控制性的要求。Web server cluster has been widely used to increase the performance of Web server. Moreover, the need for supporting Quality of Service （QoS） in Web service has become more strident recently. Differentiated service has been an active research topic in the QoS area. This paper analyzes the statistical characteristic of the request service time, and models the Web server and Web server cluster with M/G/1 FCFS queuing model. Based on the analysis of model, a solution to provide proportional stretch factor differentiated service in heterogeneous Web server cluster is designed and implemented, and a probability-space-based dispatching algorithm is proposed to dispatch requests. Requests are classified into several classes, and the average stretch factor ratios between requests classes are maintained according to their pre-specified differentiation parameters independent of the workloads. Realistic experiments show that the proposed solution satisfies the two important features of a relative differentiated service model, controllability and predictability.

关 键 词：WEB集群服务器 异构 伸展因子 相对区分服务 比例区分服务 

分 类 号：TP393.4[自动化与计算机技术—计算机应用技术]