Design and Evaluation of Dynamic Replication Strategies for a High-Performance Data Grid

Physics experiments that generate large amounts of data need to be able to share it with researchers around the world. High performance grids facilitate the distribution of such data to geographically remote places. Dynamic replication can be used as a technique to reduce bandwidth consumption and access latency in accessing these huge amounts of data. We describe a simulation framework that we have developed to model a grid scenario, which enables comparative studies of alternative dynamic replication strategies. We present preliminary results obtained with this simulator, in which we evaluate the performance of six different replication strategies for three different kinds of access patterns. The simulation results show that the best strategy has significant savings in latency and bandwidth consumption if the access patterns contain a moderate amount of geographical locality.