关键词: 数据网格, 动态复制, 复制选址, 大规模分布式资源管理

Abstract: Within data grid environments，dynamic replication is a general mechanism to improve performance and availability for distributed applications.In the paper，the authors 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，the authors propose three multiple-location strategies，which are converted into classical mathematic problems that can be solved by some famous approximation algorithms.Then，the authors explain that the strategies are suitable for resource management in the large-scale distributed resource management.

Key words: data grid, dynamic replication, replica placement, large-scale distributed resource management