Optimal Replica Selection Algorithm in Data Grid

Data replication technique in grid reduces access latency and bandwidth consumption. When different sites hold replicas of the same data, selecting the best replica is a significant benefit. In this research, the topology of Virtual Token Ring (VTR) and the VTR-based data network are presented. Then, a replica price model and a replica selection strategy are proposed. Optimal data replica is defined as the replica with the smallest transfer cost. The Buyer and Seller algorithm based on VTR network and auction protocol are also described in detail. Performance analysis demonstrates that the proposed replica selection algorithm shows a significant performance improvement over traditional replica catalog and round-robin probing based algorithm.