Optimizing File Availability in P2P Content Distribution

Jussi Kangasharju

Abstract: A fundamental paradigm in peer-to-peer (P2P) content
distribution is that of a large community of intermittently-connected nodes
that cooperate to share files.  Because nodes are intermittently connected,
the P2P community must replicate and replace files as a function of their
popularity to achieve satisfactory performance. In this talk, we develop an
analytical optimization theory for benchmarking the performance of
replication/replacement algorithms, including algorithms that employ erasure
codes. We also consider a content management algorithm, the Top-K Most
Frequently Requested algorithm, and show that in most cases this algorithm
converges to an optimal replica profile. Finally, we present two approaches
for achieving an evenly balanced load over all the peers in the community.