PeerCache - Caching Strategies for a P2P File System (P2PFS)

Gouri Joshi and Puneet Pruthi
18-845: Internet Services, Spring 2013

In today's world, data is generated at a rapid pace and at the heart
of this data generation lays the need to share it conveniently. Most
users today use Dropbox to share their data with friends and
family. However, most of the file-sharing applications rely on a
centralized server on the cloud, which could act like a bottleneck. In
this paper, we make an effort to build a read-only FUSE-based P2P
file sharing system. We explore various metadata-caching strategies
for this P2P file system. We believe that caching file attributes
along with directory listing reduces the network traffic considerably
and improves performance. We propose a combination of lazy and
proactive cache replacement strategy to evict entries in metadata
cache. We present PeerCache, a cache design policy, that shows a
reduction in execution time for sample workloads by more than 65%. We
recommend several other caching strategies that could be experimented
in a P2P file-sharing environments.