Description
In this report we present C2Cfs --- a novel collective caching architecture for distributed filesystems. C2Cfs diverges from the traditional client-server model and advocates decoupling the consistency management role of the central server from the data serving role. Our design enables multiple client-side caches to share data and efficiently propagate updates via direct client-to-client transfers, while maintaining the standard consistency semantics. We present an NFSv4-based implementation of our architecture, which works with unmodified NFS servers and requires no changes to the protocol. We also evaluate the implementation and demonstrate the performance benefits of decentralized data access enabled by our approach.