Residual-Based Measurement of Peer and Link Lifetimes in Gnutella Networks

—Existing methods of measuring lifetimes in P2P systems usually rely on the so-called Create-Based Method (CBM) [16], which divides a given observation window into two halves and samples users “created” in the first half every ∆ time units until they die or the observation period ends. Despite its frequent use [2], [17], [19], this approach has no rigorous accuracy or overhead analysis in the literature. To shed more light on its performance, we first derive a model for CBM and show that small window size or large ∆ may lead to highly inaccurate lifetime distributions. We then show that create-based sampling exhibits an inherent tradeoff between overhead and accuracy, which does not allow any fundamental improvement to the method. Instead, we propose a completely different approach for sampling user dynamics that keeps track of only residual lifetimes of peers and uses a simple renewal-process model to recover the actual lifetimes from the observed residuals. Our analysis i...

• Type: Conference
• Year: 2007
• Where: INFOCOM
• Authors: Xiaoming Wang, Zhongmei Yao, Dmitri Loguinov
• Keywords: Communications, INFOCOM 2007, Residual Lifetimes, So-called Create-based Method, Ultrapeer Lifetimes