An Effective Weighted Data Replication Strategy for Data Grid

Data Grid is a good solution to large scale data management problems including efficient file transfer and replication. Dynamic data replication in Data Grid aims to improve data access time and to utilize network and storage resources efficiently. Since the data files are very large and the Grid storages are limited, managing replicas in storages for the purpose of more effective utilization of them require more attention.In this paper, a dynamic data replication strategy, called Modified Latest Access Largest Weight (MLALW) is proposed. This strategy is an enhanced version of Latest Access Largest Weight strategy.MLALW deletes files by considering three important factors: least frequently used replicas, least recently used replicas and the size of the replica. MLALW stores each replica in an appropriate site i.e. appropriate site in the region that has the highest number of access in future for that particular replica. The algorithm is simulated using a Data Grid simulator, OptorSim, developed by European Data Grid projects. The experiment results show that MLALW strategy gives better performance compared to the other algorithms and prevents unnecessary creation of replica which leads to efficient storage usage.