基于在线模型评估的动态Web系统性能保障  

Online Model Estimating-Based Performance Guarantee Mechanism for Dynamic Web Site

作　　者：张勇[1,2] 黄涛[1,2] 陈宁江[3] 金蓓弘[1,2] 

机构地区：[1]中国科学院软件研究所软件工程技术研发中心 [2]中国科学院软件研究所计算机科学重点实验室,北京100080 [3]广西大学计算机与电子信息学院

出　　处：《软件学报》2007年第7期1660-1671,共12页Journal of Software

基　　金：国家自然科学基金No.60573126;国家高技术研究发展计划(863)Nos.2004AA112010;2003AA414310;国家重点基础研究发展计划(973)No.2002CB312005~~

摘　　要：动态多层Web系统在运行时会受到许多不确定性因素的影响.同时,在不同的负载模式下具有不同的性能特性,需要不同的性能模型进行描述.为消除不确定性因素对系统性能的影响,基于反馈控制原理设计的性能保障机制主要采用单一、固定的系统性能模型,对动态Web系统变化的性能特征考虑不够.在负载呈波动且具有不可预测特性的Internet环境中,这会降低性能目标的精确性和稳定性.采用自适应控制的思想,以满足请求平均响应时间为目标,提出了一种基于在线评估系统性能模型的保障机制,并采用两个不同类型的事务性Web测试基准,对所提方法进行了评价.结果表明,该方法能够有效减轻变化负载模式下响应时间与预期目标的偏离程度.Dynamic multi-tiered Web system can be affected by many unexpected factors during runtime. At the same time, it has different performance characteristic under different workload pattern condition. Accordingly, different performance models are needed to describe the system. Currently, performance guarantee mechanism based on feedback control theory, which aims to eliminate the effect of unexpected factors, often employs single and fixed system performance model which can not adapt to changing performance characteristics. Under fluctuant and unexpected workload condition of Internet, the method can decrease the precision and stability of performance. To guarantee anticipated response time goal, this paper presents an adaptive performance guarantee mechanism based on online estimation of performance model. Using two complementary transactional Web benchmarks to evaluate the techniques experimentally shows that the mechanism can efficiently reduce the squared departure of performance goal under varying workload.

关 键 词：动态多层Web系统 性能保障 自适应控制 在线模型评估 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]