Study On P2P Search Technology Based On Connected Dominating Set

File sharing among the end client peers through Internet is the initial purpose of peer-to-peer. In the short history of P2P applications, it has become one of the main application types that consume a large fraction of Internet traffic. P2P architecture has begun to show its capability to support massive users, and this capability makes it suitable for rapidly deploying powerful and large-scale distributed applications with low cost. How to search these end client peers in dynamic and scalable P2P architecture efficiently is the first to be solved.The basic concepts about P2P have been introduced, including the applications, the specialties, directions of research and the topology of P2P. The searching technology in P2P networks, structured topology and unstructured topology, has been presented comprehensively. Among these unstructured P2P searching technologies, the dominating set based search scheme is recited, which is proposed by Wu.The predominance and disadvantage of the dominating set based search scheme have been analyzed. To enhance its performance, a modified rule of forming dominating connected set (CDS) based search scheme has been proposed. Firstly, based on graph theory, the rules of forming the connected dominating set have been proposed, including the nodes adding rule and node marker updating rule. Some definitions adapted to P2P networks, such as node adding, sharing slave node, exclusive slave node, CDS graph with node power, and node exiting is presented. The CDS graph is proved to maintain the connection of CDS with the rules. Moreover, the algorithms of node adding and node marker updating are designed properly. Secondly, The searching scheme based on the modified dominating set formation has been designed. The term frequency of key and the number of popular files and that of the rare files provided by nodes are related in the modified searching algorithm The alternative algorithm derives the concept of k-walkers random walk, and modifies the stop condition in order to access more nodes.The computer simulation test indicates that compared with Wu's dominating set based search scheme, using the improved dominating set based search scheme provided in this thesis, under the sitution with the same hops, more nodes can be accessed and more files can be...