Optimized Lightweight Active Measurement Model on P2P Swarms Over Internet

Active measurement on peer-to-peer system is the best way to provide the real data for the system simulation and optimization. Based on coupon collector’s problem, an optimized tracing model was proposed to guide the active measurement on BitTorrent swarm. With the optimization of lowering expectations and requesting concurrently, the information repetition rate was 67.12 % off, while still covering the 95 % peers in a swarm. Moreover, the measurement time were further shortened by interacting with peers through the Distributed Hash Table and Peer Exchange. Based on the theoretical model, a lightweight measurement platform was set up to trace the 49,854 Torrentz swarms and 98 HDChina swarms over 9 months. Most of them hosted no more than 10,000 peers, and the average snapshot time on them was less than 21.4 minutes. Furthermore, the geographical characteristics, user preference and transmit performance of peers were also analyzed. Because HDChina provided Private Tracker download, so the swarm size is smaller, and peers’ distribution is more centralized, but the peer’s download speed is faster than Torrentz. Copyright © 2013 IFSA.