A Timeline Based Query-Driven Caching Protocol for Hierarchical Peer-to-Peer File Sharing Systems

摘要

In hierarchical Peer-to-Peer (P2P) systems, several selected peers are promoted as super-peers to provide an efficient lookup service for the ordinary peers, although it would cause a service bottleneck and a heavy workload at the point of the promoted peers. In this paper, we study the impact of data caches to relax such bottleneck, as well as the improvement of the trade-off point between the freshness of cached data and the maintenance cost. More concretely, we propose a Timeline based Query-Driven caching as a main contribution, which keeps the cached data up-to-date almost at any point in time with much less data transmissions than conventional methods. The performance of the proposed method is evaluated by simulation. The simulation results indicate that our caching protocol effectively reduces 52% of network traffic and shows better hit rate in smaller cache sizes.