教育资源网格中基于节点负载的副本放置策略  

Node Load Based Replication Strategy in Education Resource Grid

作　　者：姜浩然[1,2] 刘方爱[1,2] 郭磊[1,2] 

机构地区：[1]山东师范大学信息科学与工程学院,山东济南250014 [2]山东省分布式计算机软件新技术重点实验室,山东济南250014

出　　处：《济南大学学报（自然科学版）》2011年第4期377-382,共6页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金(90612003);山东省自然科学基金(Y2007G11);济南市高校院所自主创新项目(2010040072)

摘　　要：针对教育资源网格中节点存储能力和处理能力差、网络带宽分布不均的特点,提出一种基于节点负载的副本放置策略(Node Load based Education Resource Grid Replication Strategy,NLERS)。该策略按照网络带宽分布的特点分为域内和域间两部分,域内部分通过将副本放置在性能相对较高的节点来减少无效副本的创建次数,提高副本的响应时间;域间部分则通过副本在域间的扩散来减少远程副本的访问次数,提高副本响应时间。利用OptorSim模拟器构建了教育资源网格虚拟环境,分析比较了NLERS与LRU(Least Recently Used)策略、LFU(Least Frequently Used)策略和Economy-Zipf策略的性能。实验结果表明,NLERS在节点能力有限的教育资源网格中具有更好的效果。In the education resource grid （ERG）, the nodes are poor in storage and processing capacity, and the bandwidth is une- ven. To address the problem, this paper presents a node load based replication strategy （NLERS）. This strategy has two parts according to the distribution of network bandwidth, which includes inter-domain part and extra-domain part. The inter-domain strategy takes the load of nodes and the situation of the network into account, which improves the utilization ratio of the replica and decreases the remote transfer times of files. The extra - domain strategy reduces the number of visit to the remote replications by diffusion between domains. With the simulation tool OptorSim,the performances of NLERS with LRU, LFU and the Economy-Zipf strategy are compared respective- ly. The results indicate that NLERS has a better performance in ERG.

关 键 词：教育资源网格 副本创建 节点负载 网格模拟器 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]