Effectiveness of caching policies for a Web server

We look at a number of policies for managing a file system cache in a Web server. Traces from NCSA World Wide Web (WWW) server are used in this study. We study several caching policies for improving the overall performance of such a server and show that request response time can be improved by some of the replacement policies that take size of the request into account. It is shown that least frequently used (LFU) performs well when cache sizes are small (<16 MB) and SpacexAge replacement policy performs consistently better than LRU. We show that previously proposed cache sharing policies improve performance significantly in clustered Web servers.