Design And Implementation Of A CDN Web Caching System

CDN system is composed of four elements, i.e. distributed storage, load balance, network request redirection and content management. Among them, distributed storage is the basic element of CDN. Load balance, network request redirection and content management are all based on distributed storage. Through the coordination of distributed storage system, CDN can request to provide localized service for users’ access in an efficient way, which is the fundamental principles of CDN.From the view of content types, the content objects that CDN accelerates mainly include streaming media and Web page. Nowadays, although the application of streaming media is becoming more and more popular, web application remains the most basic Internet application form. Therefore, web caching optimization design has become an important way to improve CDN performance. Based on the brief introduction of the working principle of CDN, Web caching working principle and its main performance indicators, this thesis focuses on the analysis of technologies such as request redirection, distributed caching cooperation and web caching optimization, which are based on Web caching server, as the basic basis and method of CDN Web caching optimization.On the aspect of CDN Web caching system design, this thesis puts forward request redirection strategy which is based on Ant Colony Algorithm, distributed caching cooperation strategy, which is based on friendly regional cooperation, and multistage storage optimization mechanism which caters to the COSS file system.On the aspect of CDN Web cache system implementation, based on open source technology, this thesis completed the basic framework design of Web cache, as well as request redirection module and storage cooperation module which direct at CDN distributed characteristics, and a storage module that directs at the caching system individual, which can effectively identify high-frequency access Web pages and improve Web caching hit rate. Theoretical analysis of practical tests manifest that the caching system this thesis has designed and realized has obtained significant improvement in the aspects like system throughput, response speed of user page request and caching hit rate, compared with common CDN Web caching system, thus effectively improving the Internet network congestion, users’long waiting time, etc.