Hint-based cooperative caching

This paper presents the design, implementation, and measurement of a hint-based cooperative caching file system. Hints allow a decentralized approach to cooperative caching that provides performance comparable to that of existing tightly-coordinated algorithms such as N-chance and GMS, but incurs less overhead. Simulations show that the block access times of our system are as good as those of the existing algorithms, while reducing manager load by more than a factor of 15, block lookup traffic by nearly a factor of two-thirds, and replacement traffic by more than a factor of 5. We also implemented a hint-based cooperative caching file system and measured its performance with real users over the period of one week. Hint-based cooperative caching reduced the average block access time to almost half that of NFS. Moreover, our system exhibited reduced overhead and high hint accuracy as predicted by the simulations.