Based Transparent Web Cache Access Control System Design And Implementation

This article mainly introduces the project based on cache server and WCCP technology of constructing the transparent Web Cache system architecture and depend on which implementing access control based on cache server and WCCP technology using URL. One side, this project provides the caching function of Web data, which efficiently reduces network flow and improves effiency. What is more important, owe to this kind of system architecture, the URL users access can be controlled so that the content on the Internet which is not good can be controlled depend on the flexible and efficient access control policy.This design follows the transparent principle that not to change the network topological and the network using mode of users, makes good use of the advantage of the open source technology, researches the protocol such as WCCP , GRE and Squid cache engine with its plugin technology on linux environment. Also, using Squid cache server as the access control infrastructure, on the base of understanding its working theory and disadvantage this research implements the efficient redirect plugin of its own depends on the standard of Squid plugin interface to improve the URL matching efficiency on the condition of high capacity and load. So that, the design and implement of URL access control system based on transparent Web Cache this article introduces is of high value to be research and applicated.This article first introduces several basic concepts and principles on Web Cache and its developing course, then mainly about the network architecture design of transparent Web Cache, and based on which the design and implement of user access control. This project basically includes several parts below: 1. the design and implement of transparent Web Cache network architecture ;2. the working principle of Squid cache engine and the research to its plugin interface standard; 3. the design and implementof user access control redirect plugin. In which the transparent Web Cache basic network architecture is working on linux operating system and Squid cache engine, with router which sustain WCCP protocol to implement the transparent redirect of cache flow; Squid is a efficient proxy cache server software on linux, besides working as a proxy cache which supports HTTP FTP gopher WAIS communication protocol, it can be used as the DNS cache to quicken the transform between network address and its IP address. Its consists of a main service program Squid a DNS query program dnsserver several rewriting request and certificating programs and some manage tools. The implement of user access control based on blacklist works as a plugin to Squid cache engine to extend and enhance the function of Squid, which is mainly about user management blacklist access control log record and alert system blacklist maintenance and cache digging and so on.Finally , this article summarizes the developing obstacles on this network architecture, discusses the ways to solving this problems, points out the research aspect and develop trend to guide the research in the future.