| 摘要: |
| 教育资源网格是解决目前分布式教育资源共享问题的有效手段.针对中小学教育资源共享问题,提出了层次式的教育资源网格模型,定义了各层节点的功能.通过与欧洲数据网格对比,分析了教育资源网格的特点.基于层次式的教育资源网格,对影响副本创建策略性能的因素进行了分析,然后引入网络带宽和文件大小两个参数,提出了一种动态副本创建策略(dynamic replica creation strategy,简称EDRS).利用数据网格模拟工具OptorSim构建了教育资源网格虚拟环境,分析比较了EDRS策略与Caching-LRU策略、Caching-LFU策略和基于经济模型的副本创建策略的性能.最后,综合各项指标分析了不同策略对教育资源网格系统性能的影响.结果表明,EDRS策略在教育资源网格应用中有着更好的系统性能. |
| 关键词: 教育资源 网格 副本创建 层次式 资源共享 |
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| 基金项目:Supported by the National Natural Science Foundation of China under Grant Nos.60373063, 90612003 (国家自然科学基金); the Shandong Provincial Natural Science Foundation of China under Grant No.Y2007G11 (山东省自然科学基金) |
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| Education Resource Grid Model and Replica Creation Strategies |
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XING Chang-Ming,LIU Fang-Ai,YANG Lin,LI Wen
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| Abstract: |
| The education resource grid is an effective measure to solve the problem of sharing distributed education resources at present. First, with regard to the education resource sharing in secondary and elementary schools, a hierarchy model of education resource grid is proposed and the functions of nodes in each layer are defined in this paper. By comparing with the European Data Grid, the education resource grid is analyzed with its characteristics. Then based on the hierarchy grid model, some factors, which influence the performance of replica creation strategy, are analyzed and a dynamic replica creation strategy (EDRS) is proposed by introducing two parameters, i.e., the network bandwidth and file size. With the data grid simulation tool OptorSim, the performances of EDRS with Caching-LRU, Caching-LFU and the economic model strategy are compared respectively. At last, the influence of different strategies on the performance of the education resource grid system is analyzed by synthesizing each parameter. The result indicates that the EDRS has a better system performance in applications of the education resource grid. |
| Key words: education resource grid replica creation hierarchy resource sharing |
