Storage and Content Distribution in Cooperative Environments

Motivation and Approach

Peer-to-peer Internet applications for data sharing have gained in popularity over the last few years to become one of today's main sources of Internet traffic. Although the goal of most P2P systems is to provide general distributed resource sharing among the participating peers, two of the most popular applications are shared storage and content distribution. In such systems, participating nodes, some of them contributing storage space, form a self-organized overlay network over which clients' requests, servers' replies and content are distributed.

The success and increased popularity of such P2P services keeps challenging the research community. We have been investigating a number of approaches to ensure the sustainable scalability of these applications - from new organizations protocols and query-related strategies resilient to the expected high-level of peer transiency, to better scheduling algorithms for handling request on contributing peers.

Existing peer-to-peer systems rely on overlay network protocols for object storage/retrieval and message routing. These overlay protocols can be classified broadly as either structured or unstructured based on the constraints imposed on how peers are organized and where stored objects are kept. The research community continues to debate the pros and cons of these alternative approaches. We have contributed to this discussion the first multi-site, measurement based study of two operational and widely deployed P2P file-sharing systems.





  • Peer Lifespan Trace - Trace of the lifespans, or session lengths, of peers in the Gnutella network collected, through active measurement, during March 2003.

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