On long-term social relationships in peer-to-peer systems

BitTorrent, the most popular file delivery system over the Internet, has attracted attention from network operators and researchers for its wide deployment. Recent studies suggest that long-term relationships among BT peers could be explored for peer cooperation, as to achieve better sharing efficiency. However, whether such long-term relationships exist remain unknown. In this paper, we for the first time examine the feasibility of social network based content delivery through the study of Twitter initialized/shared torrents. We show that the peers in such swarms have stronger temporal locality, thus offering great opportunity for improving their degree of sharing. Based on the Hadamard Transform of peers' online behaviors, we develop a social index to quickly locate peers of common patterns. Preliminary PlanetLab experiments indicate that the incorporation of social relations remarkably accelerates the downloading time. The improvement remains noticeable even in a hybrid system with a small set of socially active peers only.