Evaluation of Performance of Cooperative Web Caching with Web Polygraph

This paper presents a framework for evaluating the performance of cooperative Web cache hierarchies. Web Polygraph is employed to provide an environment for simulation, to generate desired workloads, and to obtain performance statistics from the standpoint of clients and servers. Squeezer, a proxy cache log analysis tool, provides detailed cache statistics including information about cache cooperation. Dummynet toolkit is used to manage network properties and simulate realistic network conditions. The result is a flexible framework that can analyze the performance of a given cache hierarchy on a given workload under given network conditions. All experiments are repeatable and results with different configurations can be compared. We describe our evaluation methodology and report our experience in employing it to compare cache hierarchies built with Squid proxy cache servers.