Improving End - to - End Performance of the Web Using Server Volumes and Proxy Filters 3

The rapid growth of the World Wide Web has caused serious performance degradation on the Internet. This paper ooers an end-to-end framework by collectively examining the Web components { clients, proxies, servers, and the network. Our goal is to reduce user-perceived latency and the number of TCP connections, improve cache coherency and cache replacement, and enable prefetching of resources that are likely to be accessed in the near future. In our scheme, server response messages include piggybacked information customized to the requesting proxy. Our enhancement to the existing request-response protocol does not require per-proxy state at server or per-server state at the proxy, and can be implemented without changes to HTTP 1.1. The server groups related resources into volumes (based on access patterns and the le system's directory structure) and applies a proxy-generated lter (indicating the type of information of interest to the proxy) to tailor the piggyback information. We present eecient data structures for constructing server volumes and applying proxy lters, and a transparent way to perform volume maintenance and piggyback generation at a router along the path between the proxy and the server. We demonstrate the eeectiveness of our end-to-end approach by evaluating various volume construction and ltering techniques across a collection of large client and server logs.