并行文件系统客户端缓存对系统I/O性能的影响  

Analysis of I/O performance of client caching in parallel file system

作　　者：伍卫国[1] 张虎[1] 方敏[1] 万群[1] 钱德沛[1] 

机构地区：[1]西安交通大学电子与信息工程学院,陕西西安710049

出　　处：《华中科技大学学报（自然科学版）》2006年第z1期144-147,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家高技术研究发展计划资助项目(2004AA111110);西安网络结点建设资助项目(2002AA104550)

摘　　要：对浪潮天梭并行文件系统(LCTS-PFS)客户端缓存性能进行了测试,提出了多客户端访问、带客户端缓存的并行文件系统排队模型.分析了不同缓存命中率、不同缓存空间大小和不同文件长度情况下,客户端缓存对I/O响应时间的影响.分析结果表明:I/O响应时间随缓存命中率提高而减少且在有/无缓存情况下的I/O响应时间曲线存在唯一交点,在此交点之前无缓存情况下I/O响应时间小于有缓存情况,而交点之后结果相反;缓存命中率不发生变化时,缓存空间越大I/O响应时间越长;相比无缓存情况下I/O响应时间,若客户端请求生成率固定,则访问文件越大,缓存对I/O响应时间提升越少;若请求生成率发生变化,则相同缓存命中率情况下,访问的文件越大缓存对I/O响应时间提升越多.性能测试和理论分析一致.The design and implementation of client caching in LCTS-PFS was introduced,and the performance results were present.In the end,the influence on system I/O performance of client caching is concluded.I/O response time is one of the most important criterions of Parallel File System.Based on the Parallel File System queuing model with multi-client accessing and client-caching,the analysis of the influence on I/O response time of client caching was presented by changing the cache hit rate,the cache size and the file size. The conclusions are as follows: First,the higher the cache hit rate,the smaller the I/O response time,and the curves of the I/O response time with and without client caching has a point of intersection.The most important thing is that before the two curves intersect,the I/O response time without client caching is less than that with client caching;But after the two curves intersect,the phenomena is totally opposite.Second,the bigger the cache size,the longer the I/O response time with the cache hit rate remaining the same.Third,the bigger the file size,the smaller the improvement on the I/O response time by client caching if the client require produce rate remains the same.And the bigger the file size,the bigger the improvement on the I/O response time by client caching when the client require produce rate changes and the cache hit rate remains the same.The performance result turns out to be consistent with the analysis result.

关 键 词：并行文件系统 客户端缓存 排队论 I/O 响应时间 

分 类 号：TP393.02[自动化与计算机技术—计算机应用技术]