Analysis of session sequences of stable peers in P2P systems

This paper presents a formal definition of stable peers, a novel method to separate stable peers from all peers and an analysis of the session sequences of stable peers in P2P (Peer-to-Peer) systems. This study uses the KAD, a P2P file sharing system with several million simultaneous users, as an example and draws some significant conclusions: (1) large numbers of peers with very short session time usually possess few sessions; (2) the stable peers is about 0.6% of all peers; (3) the 70% of stable peers possess very long total session time ensured by a large number of sessions, and possess large difference between session time; (4) the 30% of stable peers, whose average session time is 1.8 times of the former, possess long total session time, a small number of sessions and high availability. We believe that these two types of stable peers can be used for different functions to solve the churn problem in the hierarchical P2P systems.