An Effective Search Scheme for Gnutella-Like P2P Networks

Abstract

In Gnutella-like P2P networks, blind flooding causes a large number of redundant messages, and this makes such networks not scalable. Previous researchers noticed three types of nodes in P2P networks: super nodes which share a large number of resources and tend to have long online time, stable nodes sharing a number of resources and having long online time, and dynamic nodes that share few resources and have short online time. Then they utilize an analytical model and simulation to obtain the result that, to keep search efficiency of P2P systems high, the resources of super and stable nodes can serve queries in large areas and the resources of dynamic nodes can only serve queries in local areas. Based on the above result, we present a new Differentiated Publishing (Diff-Publishing) architecture to make search efficiency of Gnutella-Like P2P systems high. The introduced network is a two-tier topology, neighbor overlay aims to let the resources of dynamic nodes serve queries in local areas, and semantic overlay tries to congregate the semantic relevant stable and super nodes to answer queries in large areas. Given a query, Diff-Publishing first routs it to the query generator's neighbors, and if it fails to hit the targets, it will be forwarded to the relevant semantic overlay. Simulation results show that the proposed search scheme greatly improves search efficiency of P2P networks while introducing only modest maintenance cost.