Content-oriented topology restructuring for search in p2p networks

This article presents a new algorithm for content-oriented search in P2P networks that avoids flooding and thus ensures scalability. It is based on the concept of small worlds: peers are enabled to actively influence network structure by choosing their neighbours. Different strategies for neighbour selection are possible, the most important being the one called ”cluster strategy”, which consists in peers choosing other peers that offer content similar to their own. Thus, peers will organize into clusters of semantic similarity. This will (as has to be shown) result in a small world network structure. This structure can then be exploited for implementing an efficient search algorithm: each peer forwards incoming queries to just one of its neighbours (the one whose document profile best matches the query). Because paths are short in small worlds and because there are semantic clues for finding them, it will be possible to quickly redirect queries to the right clusters of peers. After giving a detailed overview of related ideas and introducing the exact algorithm, a model of a peer-to-peer network will be presented that makes some simplifying assumptions about the world and thus allows us to build a simulation of our algorithm. The experimental setup of this simulation will be explained in detail and simulation results will be given and thoroughly discussed.