A Statistical Study of Today's Gnutella

As a developing P2P system, Gnutella has upgraded its protocol to 0.6, which significantly changed the characteristics of its hosts. However, few previous work has given a wide-scale study to the new version of Gnutella. In addition, various kinds of P2P models are used to evaluate P2P systems or mechanisms, but the reliability of some hypotheses used in the models are not carefully studied or proved. In this paper, we try to remedy this situation by performing a large scaled measurement study on Gnutella with the help of some new crawling approaches. In particular, we characterize Gnutella by its queries, shared files and peer roles. Our measurements show that the assumption that query arrival follows Poisson distribution may not be true in Gnutella and most peers incline to share files of very limited types, even when MP3 files are excluded. We also find that many ultrapeers in Gnutella are not well selected. Statistical data provided in this paper can also be useful for P2P modeling and simulation.