Detection and exploitation of file working sets

Abstract

The work habits of most individuals yield file access patterns that are quite pronounced and can be regarded as defining working sets of files used for particular applications. This paper describes a client-side cache management technique for detecting these patterns and then exploiting them to successfully prefetch files from servers. Trace-driven simulations show the technique substantially increases the hit rate of a client file cache in an environment in which a client workstation is dedicated to a single user. Successful file prefetching carries three major advantages: (1) ap- plications run faster, (2) there is less ''burst'' load placed on the network, and (3) properly-loaded client caches can better survive network outages. Our technique re- quires little extra code, and — because it is simply an augmentation of the standard LRU client cache management algorithm — is easily incorporated into existing software.