Replication Strategies in Peer-to-Peer Services over Power-law Overlay Networks

Many services have recently been offered based on a peer-to-peer (P2P) communication model. The robustness of the P2P network against frequent peer failure must be considered. Replication of the content is one of the most useful techniques to increase robustness. However, the overall effectiveness of replication is heavily dependent on the topology of the logical network. As topology of networks, including the Internet and P2P, follows a Power-Law distribution pattern, we first investigate the effect of the logical network topology (especially of the Power-Law characteristics) on replication methods. Based on these observations, we propose a query forwarding method that considers the characteristics of the network topology in order to improve the performance of the P2P service. Our simulation results show that our proposed method can greatly improve the query performance by considering the characteristics of Power-Law. Our method reduces the average hop count in finding replicas by up to 60% compared with the random forwarding method.