On Request Forwarding for the Dynamic Web Caching Hierarchies

To enhance the performance of Web caching, we proposed a dynamic Web caching hierarchy scheme based upon the Caching Neighborhood Protocol (CNP) [1][2] to facilitate establishing flexible cooperation partnerships among the Web origin servers and proxy servers. One of the key issues to the success of using CNP for the Web caching is request forwarding, i.e., to which destination server a client-side proxy server should forward the request that resulted in a cache miss. Hence, we introduce the concept and the properties of pyramid set, which consists of the most frequently accessed Web origin servers as observed by a proxy server, to construct the request forwarding tables for the client-side proxy servers. By examining the proxy server traces, we proposed and investigated several heuristics for selecting a server among a group of candidates to forward the request to. A simple scheme as well as a family of hybrid schemes considering both the request access distributions of the previous d..