A Case for Dynamic Selection of Replication and Caching Strategies

Replication and caching strategies are being used to reduce user perceived delay and wide area network traffic. Numerous such strategies have been proposed to manage replication while maintaining consistency among the replicas. In earlier research, we demonstrated that no single strategy can perform optimal for all documents, and proposed a system where strategies are selected on a per-document basis using trace-driven simulation techniques. In this paper, we demonstrate the need for continuous dynamic adaptation of strategies using experiments conducted on our department Web traces. We also propose two heuristics, Simple and Transition, to perform this dynamic adaptation with reduced simulation cost. In our experiments, we find that Transition heuristic reduces simulation cost by an order of magnitude while maintaining high accuracy in optimal strategy selection.