Dynamic Swarm Management for Improved BitTorrent Performance

BitTorrent is a very scalable file sharing protocol that utilizes the upload bandwidth of peers to offload the original content source. With BitTorrent, each file is split into many small pieces, each of which may be downloaded from different peers. While BitTorrent allows peers to effectively share pieces in systems with sufficient participating peers, the performance can degrade if participation decreases. Using measurements of over 700 trackers, which collectively maintain state information of a combined total of 2.8 million unique torrents, the authors identify many torrents for which the system performance can be significantly improved by re-allocating peers among the trackers.