P2p-based Content Distribution Network And Cache Replacement Algorithm

CDN (Content Distribution Network) and P2P are two main ways of delivering contents on the Internet. The key of CDN is to deliver contents of ICP or e-commerce sites to service nodes closing to users quickly and efficiently, so that the fast response can be guaranteed. Moreover, CDN helps to reduce the load of sites and improve the utilization of equipments and networks. Compared with CDN, P2P networks have no central servers, each node (called peer) not only can work as a client and use services from other nodes but also can work as a server to supply services. Obviously, the merits of CDN (reliability and manageability) and that of P2P (scalability) are complementary each other, hence how to combine such two techniques effectively becomes one of current researching hotspots of networks. This paper proposes an autonomous cache system of P2P-based CDN network by combining the merits of P2P and CDN. The new system can not only effectively reduce the accessing traffic to proxy servers, increase the capacity of the cache system, and degrade the overall costs, but also can transfer the Web contents to the autonomy of users so that the accessing speed can be improved greatly. The main works of this paper include:(1) Make in-depth analysis and search on the CDN and P2P techniques.(2) Propose a new prototype of network topology, namely autonomous cache system of P2P-based CDN network.(3) Put forward a smart cache replacement algorithm based on the accessing property of network users and the evaluation of network documents. The proposed co-operation caching system holds the double properties of P2P and CDN, and addresses the redundancy and the single-point failure problems effectively. Accessing properties of users, values of network documents, life of documents, redundancy of cache documents and size of documents are taken account in smart cache replacement algorithm, so it can achieve high cache hit rate with low computing complexity.(4) All algorithms in the paper are simulated in appropriate ways.