Prices are right: managing resources and incentives in peer-assisted content distribution
Michael J. Freedman, Christina Aperjis, Ramesh Johari · 2008
Abstract We present a novel design for a peer-assisted content distri-bution system that addresses two key shortcomings of existing proposals. First, our system explicitly identifies therelative demand for files: users are rewarded for sharing more popular content. Second, our system efficiently uti-lizes network resources, by considering resource constraints explicitly when matching downloaders and uploaders. Underlying our system is a market-based mechanism thatenables the efficient allocation of network resources across multiple files. Although we price files and employ a vir-tual currency, these are purely an algorithmic ploy: the system clients hide the market details from the user. Neverthe-less, our design also naturally incentivizes the contribution of scarce resources. More importantly, our design endoge-nously adapts peers ' behaviors to changing environments, a critical advantage for real-world deployments in which net-work conditions, participation rates, resource demands, and content are continually in flux. 1 Introduction Peer-to-peer (P2P) content distribution systems have beenwidely successful for scalable file sharing across the Internet, quickly delivering popular content to large numbers ofusers and reducing costs for content providers in the process. Traditional P2P designs have been overly focused onperformance optimization, however, without addressing the overall welfare of participants. Scant attention is devoted toasking which files are "most useful " to disseminate, where resource congestion or network costs are accumulating, andwho is providing useful content to the system.