An Efficient Data Replication Strategy in Large-Scale Data Grid Environments Based on Availability and Popularity

The data grid technology, which uses the scale of the Internet to solve storage limitation for the huge amount of data, has become one of the hot research topics. Recently, data replication strategies have been widely employed in distributed environment to copy frequently accessed data in suitable sites. The primary purposes are shortening distance of file transmission and achieving files from nearby locations to requested sites so as to minimize retrieval time and bandwidth usage. In this paper, we propose a new replica selection strategy, which based on response time and security. However, replication should be used wisely because the storage size of each Data Grid site is limited. We also present a new replica replacement strategy based on the availability of the file, the last time the replica was requested, number of access, and size of replica. The simulation results report that the proposed strategy can effectively improve mean job time, bandwidth consumption for data delivery, and data availability as compared with those of the tested algorithms.