| Presently, distributed application based on the Internet has become one kind of mainstream application pattern. At the same time, Peer to Peer network as a typical important network structure has great impact on the development of distributed network applications. In recent years, P2P network technology has been applied to many fields such as file-sharing, P2P computing, search engines and collaborative work etc. File-sharing is main reason for the emergence of P2P network technology, and is also one of the most important aspects of P2P network applications. P2P file-sharing system allows any two computers on the Internet to directly share documents, multimedia, and other documents. In P2P file-sharing systems, resource searching has been one of the key techniques of P2P network, and a hot research topic. The extensive literature has been put forward to improve existing resource searching algorithms. However, in the efficiency of resource searching and the accuracy of its location in P2P networks, there are still lots of work to do.At the same time, mobile agent technology as an emerging distributed computing paradigm combines computer network and artificial intelligence, and introduces a new idea for resource searching, so that users of P2P networks have more automated and intelligent applications. Mobile agent that is embedded in the P2P networks can help users complete resource searching tasks, and make resource searching have numerous advantages, such as variety,synchronism,expansibility,effectiveness and comprehensive etc.The existing resource searching methods have several disadvantages, such as the use of high network bandwidth, long latency, and instability of resource searching because of peers dynamically joining and leaving the network. This paper proposes a two-tiered network model of P2P file-sharing systems based on Super-Peer architecture. And on the basis of the model, this paper also proposes an improved resource searching approach based on mobile multi-agent. The main our work is described as follows:(1)This paper summarizes the advantages and disadvantages of the existing P2P file-sharing systems, introduces mobile Agent technology, and proposes an improved model of P2P file-sharing system that is based on the dynamic collaboration of mobile multi-agent. In order to reduce the network load of query node and take into account the different performance and network bandwidth of each node, the model uses the hybrid structure P2P network including Common-Peer layer and Super-Peer layer. It does not depend on any central server to work and improve stability of networks.(2)This paper describes the network structure of improved system model and introduces the structure and function of the model of system in detail.(3)This paper analyses the current mainstream resource searching algorithms of P2P networks. According to advantages of mobile agent technology for resource searching, the proposed algorithm optimizes the mechanism of resource location and discovery of P2P network based on mobile Multi-agents. In the process of resource searching, mobile agent makes full use of its advantage, such as mobility, interaction and collaboration etc., to share tasks and intermediate results, and integrate the similar queries. It improves the algorithm of resource searching, reduces the traffic of the network, improves the efficiency of resource searching, and alleviates the load of the network nodes. In addition, According to the current state of network and the users'work conditions, the mobile agent can self-regulate the response time and adjust intelligently its path. So that it can make the expansibility of network better. Finally, the experimental results show that our approach is feasible and effective. Zuo Zongle (Computer Application Technology) Supervised by Prof. Wang Zhongqun... |
