Resolving the Noxious Effect of Churn on Internet Coordinate Systems

Internet Coordinate Systems (ICS) provide easy and practical latency predictions in the Internet. However, peer dynamics (i.e, churn), which is an inherent property of peer-to-peer (P2P) systems, affects the accuracy of such systems. This paper addresses the problem of churn in an ICS without landmarks, like Vivaldi. We propose a framework to assess the robustness of such an ICS in the presence of churn, and evaluate two models for handling churn. The key idea is to reactively recover lost neighbours, either by picking new nodes at random, or by selecting a new one among the node’s two-hop neighbours, while maintaining high reliability and low communication overhead. We then show by simulations that our models mitigate the impact of churn, and lead to a good accuracy compared to an instance of an ICS running without churn.