Comparison of function based web proxy cache replacement strategies

Most Web proxy caches use simple cache replacement techniques like least recently used. This technique although simple is not necessarily the most efficient. Function based cache replacement strategies are more sophisticated. They consider recency, frequency, and size attributes of Web objects to make replacement decisions. In this paper we provide a comprehensive study to compare eight of the most well known function based Web proxy cache replacement strategies. We use the two most important performance metrics, hit rate and byte hit rate, to evaluate these techniques. We also introduce a new performance metric; the object removal rate, which is an indication of CPU usage and disk access at the proxy server. Our study provides valuable insights for both industry and academia. They are especially important for Web proxy cache system administrators.