Replication algorithms for the World-Wide Web

This paper addresses the two fundamental issues in replication, namely deciding on the number and placement of the replicas and the distribution of requests among replicas. We first introduce a centralized algorithm for replicating objects that can keep a balanced load on sites. In order to meet the requirement due to the dynamic nature of the Internet traffic and the rapid change in the access pattern of the World-Wide Web (Web), we also propose a distributed algorithm where each site relies on some collected information to decide on where to replicate and migrate objects to achieve good performance. The performance of the proposed algorithms is evaluated experimentally and a comparison of their measured performance is presented.