Optimized Peer-to-peer File Exchange The System Optimizationpeer Principles And Design

P2P is the abbreviation of Peer-to-Peer, which is a new distributed computing model. In this model, peers can share computing resources of others equally.P2P system is a kind of distributed system, in which every peer both provides services to others and gets services from others. The resources that are exchanged may be files, messages, storages and CPU circles. A P2P system is dynamic, and each peer can log in or log out it at any moment.With the development of network technology, P2P has become a hot topic in computer science, and some software based on P2P has been developed by some companies. The characteristics of P2P systems include decentralization, scalability, robustness, availability, adaptation, load balance and anonymity. The applications of P2P include file-sharing, P2P computing, cooperating, instant messages, searching engines, network games, etc. P2P is not mature, and a lot of problems need to be solved. The topic of this paper is P2P file-sharing system, which is the most important application of P2P.In this paper, we propose an efficient P2P file-sharing system named OptimizationPeer, which includes some advanced technologies. Our contributions include:1. We introduce the basic knowledge of P2P and summarize the 4 main research issues about P2P. We analyze the advantages and shortcomings of current P2P systems, and sum up the 4 main elements which influence the efficiency of P2P file-sharing systems. They are network topology, mode of query, message routing and the mode of file-downloading.2. We propose an efficient P2P file-sharing system model named OptimizationPeer, whose efficiency is improved from the following 4 aspects:(1) We proposed a P2P network based on interests, which embodies the Power Law and the Characteristic of Small World. We provide the definition and formula about the Degree of Similitude of Interests (DSI). In addition, we provide some policies about the dynamic network.(2) We use the method of Distributed Breath First Search (DBFS) to process the problem of messages transmitting. Additionally, we provide 3 policies about routing better.(3) Using the technologies of abstracting and integrating meta-data, OptimizationPeer stores meta-data of shared files on Super-peers in XML schema, so it supports the complex query based on XQuery.(4) The efficiency of file transmitting is much improved by using the technology of...