Availability in BitTorrent Systems

— In this paper, we investigate the problem of highly available, massive-scale file distribution in the Internet. To this end, we conduct a large-scale measurement study of BitTorrent, a popular class of systems that use swarms of actively downloading peers to assist each other in file distribution. The first generation of BitTorrent systems used a central tracker to enable coordination among peers, resulting in low availability due to the tracker’s single point of failure. Our study analyzes the prevalence and impact of two recent trends to improve BitTorrent availability: (i) use of multiple trackers, and (ii) use of Distributed Hash Tables (DHTs), both of which also help to balance load better. The study measured over 20,000 torrents spanning 1,400 trackers and 24,000 DHT nodes over a period of several months. We find that both trends improve availability, but for different and somewhat unexpected reasons. Our findings include: (i) multiple trackers improve availability, bu...

• Type: Conference
• Year: 2007
• Where: INFOCOM
• Authors: Giovanni Neglia, Giuseppe Reina, Honggang Zhang, Donald F. Towsley, Arun Venkataramani, John S. Danaher
• Keywords: Communications, INFOCOM 2007, Multiple Trackers, Trackers Improve Availability, file Distribution