Implementation and performance of cluster-based file replication in large-scale distributed systems

The authors describe the implementation and an initial performance study of Frolic, a cluster-based dynamic file replication system. This system specifically targets large scale commercial environments with extensive file sharing, although it is expected to also perform well in systems with limited file sharing as well. Instead of keeping copies of a widely shared file at each client workstation, these files are dynamically replicated onto the cluster file servers, so that they become locally available. The costs of maintaining consistency among the limited number of server copies should be much less than that among a large number of clients. The problems of network and server congestion as well as that of high access latency may be alleviated. Simulation studies using a statistical workload have shown that cluster-based file replication can significantly reduce file access times for a wide range of workload parameters