Committee: Reza Rejaie (Chair), Andrzej Proskurowski, Virginia Lo, David Levin, Walter Willinger
Dissertation Defense(Oct 2017)
Keywords: measurement; P2P
Peer-to-peer systems are becoming increasingly popular, with millions of simultaneous users and a wide range of applications. Understanding existing systems and devising new peer-to-peer techniques relies on access to representative models, derived from empirical observations, of user behavior and peer-to-peer system behavior on a real network. However, it is challenging to accurately capture behavior in peer-to-peer systems because they are distributed, large, and rapidly changing. While some prior work does study the properties of peer-to-peer systems, they do not quantify the accuracy of their measurement techniques, sometimes leading to significant error.
This dissertation empirically explores and characterizes a wide variety of properties of peer-to-peer systems. The properties examined fall into four groups, along two axes: properties of peers versus properties of how peers are connected, and static properties versus dynamic properties. To study these properties, this dissertation develops and assesses two measurement techniques: (i) a crawler for capturing global state and (ii) a Metropolized random walk approach for collecting samples. Using these techniques to conduct empirical studies of widely-deployed peer-to-peer systems, this dissertation presents empirical results to suggest useful models for key properties of peer-to-peer systems. In the end, this dissertation significantly deepens our understanding of peer-to-peer systems and lays the groundwork for the accurate measurement of other properties of peer-to-peer systems in the future.