Transparent distributed Web caching with minimum expected response time

Web caching is a standard approach to improving the performance and quality of Web services. The effectiveness of a single cache in this environment, however, is relatively low. Cache hit rates of 40% or lower are typical in the Web. Distributed caching seeks to improve the effectiveness of Web caching by supporting the sharing of data across multiple cache servers. We describe the minimum expected response time (MRT) distributed Web caching scheme. MRT uses a layer 5 switch to redirect cacheable HTTP requests transparently to the cache server with the minimum expected response time. The response time estimate produced is based on information about cache server content, cache server workload, Web server workload and network latency. We present simulation experiments to show that MRT outperforms existing distributed Web caching schemes in terms of average HTTP request response times.