Intra-communication squid web proxy cache cluster as single proxy server

Abstract

To construct a high performance proxy server, one of the choices is proxy cluster. Many member servers in cluster can share workload from client. Although the throughput can increase, the overall hit ratio will drop significant because cache object is duplicated in difference and thus decreases the efficient cache storage. Squid web proxy cache supports ICPv2 (Internet Cache Protocol, Version 2). ICP is a lightweight protocol that can quickly query the existence of object from other proxies. So the problem of hit ratio decay can be solved by enable ICP in Squid. In this project a proxy cluster configuration which function equivalent to single proxy server is proposed. This configuration has the characteristic of single proxy server, but higher availability and flexibility. The cluster composes by a L7 switch (Linux with Linux virtual server and netfilter/iptables) and many member servers (Squid running on Linux and ICP is enabled). An optimum setup will be found out with the help of Web Polygraph benchmarking program.