【摘要】 动态复制技术对于提高数据网格的性能是非常重要的。对目前的动态复制策略进行了综述,鉴于目前效果较好的动态复制策略均为单选址算法,对于延迟较大、分布较广的网格存在很大局限性。提出了三种多选址的动态复制策略,并将它们转化为经典的数学问题进行求解。在给出了多选址动态复制策略在远程教育资源管理中的应用后,在欧洲数据网格试验床1拓扑上进行了仿真实验,实验结果表明:与目前效果较好的选址策略相比,所提出的多选址策略对于减少网络负载和网络延迟效果显著。更多还原

【Abstract】 Within data grid environments,dynamic replication is a general mechanism to improve performance and availability for distributed applications.In the paper,we firstly review the dynamic replication strategies till now.As the experimentally efficient strategies are based on single-location algorithms,they are not suitable for geographically broad grids with long latency.To address such issues,three multiple-location strategies are proposed,which are converted into classical mathematic problems that can be solved by some famous approximation algorithms.After explaining the strategies are suitable for resource management in the remote education,we do some experiments in the topology of EU Data Grid Testbed 1.The simulation results demonstrate that our multiple-location strategies significantly improve the bandwidth consumption and access latency in data grid.更多还原