Main memory caching of Web documents

Abstract

An increasing amount of information is currently becoming available through World Wide Web servers. Document requests to popular Web servers arrive every few tens of milliseconds at peak rate. To reduce the overhead imposed by frequent document requests, we propose the notion of caching a World Wide Web server's documents in its main memory (which we call Main Memory Web Caching). We show that even a small amount of main memory (512 Kbytes) that is used as a document cache, is enough to hold more than 60% of the documents requested. We also show that traditional file system cache management methods are inappropriate for managing Main Memory Web caches, and may result in poor performance. Based on trace-driven simulations of several server traces we quantify our claims, and propose a new cache management that dynamically adjusts itself to the clients' request pattern and cache size. We show that our policy is robust over a variety of parameters and results is better overall performance.