Collaborative delay-aware scheduling in peer-to-peer UGC video sharing

We have recently witnessed an explosion of user-generated content (UGC) sharing, particularly video clips, as the new killer Internet application. Given the sheer amount of resource demands, the peer-to-peer (or peer-assisted) model has been suggested for this new service scenario. There are however a series of unique challenges from the UGC videos to be addressed, in particular, their significantly shorter lengths. As such, any delay, even being minor as compared to those for conventional movie-like videos, will be perceptually amplified. Given the much more stringent delay requirement, the UGC video sharing thus calls for sophisticated scheduling to provide quality playback. In this paper, we propose a novel collaborative delay-aware scheduling (CODAS) that is customized for the short UGC videos. CODAS improves playback quality and reduces server workload, through adaptive prioritization of data requests and tighter collaboration between peer suppliers and the server. We present detailed design and optimization of CODAS, particularly the synergy policies in different zones of a shrinking window. We evaluate it through extensive trace-driven simulations and PlanetLab prototype experiments, and the results show the great improvement over the state-of-the-art solutions.