Analysis of search and replication in unstructured peer-to-peer networks

Abstract

This paper investigates the effect of the number of file replicas on search performance in unstructured peer-to-peer networks. We observe that for a search network with a random graph topology where file replicas are uniformly distributed, the hop distance to a replica of a file is logarithmic in the number of replicas. Using this observation we show that flooding-based search is optimized when the number of replicas is proportional to the file request rates. This replica distribution is also optimal for download time and since flooding has logarithmically better search time than random walk under its optimal replica distribution, we investigate the query-processing load using this distribution.