Capturing accurate snapshots of the Gnutella network
Daniel Stutzbach, Reza Rejaie · 2006
A common approach for measurement-based characterization of peer-to-peer (P2P) systems is to capture overlay snapshots using a crawler. The accuracy of captured snapshots by P2P crawlers directly depends on both the crawling speed and the fraction of unreachable peers. This in turn affects the accuracy of the conducted characterization based on these captured snapshots. Prior studies frequently rely on crawling the network over an hour or more, during which time the overlay may change substantially. Moreover, none of the previous measurement-based studies on P2P systems have examined the accuracy of their captured snapshots or the impact on conducted characterization. In this paper, we present a fast P2P crawler called Cruiser, discuss aspects of its design, and evaluate its accuracy. Cruiser is able to crawl the million-node Gnutella network in around 7 minutes. Having these accurate snapshots enables us to quantify (i) the "relative error" in captured snapshot as a function of crawling speed, (ii) the tradeoff between the completeness and accuracy of captured snapshots, and (iii) the effect of snapshot accuracy on the correctness of characterizations of Gnutella.