无结构P2P覆盖网络的拓扑优化

研究了全分布无结构P2P(peer-to-peer)网络拓扑的最优化问题.通常认为,无结构P2P网络拓扑属于Power-Law结构.然而,Power-Law并非对所有应用都是最好的选择.首先研究了无结构P2P覆盖网络结构对无结构P2P搜索的影响,给出了结点度分布、访问频率模式和搜索成功率之间的关系.然后基于数据访问频率分布,给出了结点度的优化分布模型.实验结果表明,该无结构P2P拓扑优化结构在提高搜索成功率方面是有效的.该工作对构造合理的覆盖网络拓扑具有重要意义,同时将加深对无结构P2P环境下数据部署问题的认识.

Optimization of Overlay Topology for Unstructured Peer-to-Peer

This paper addresses the issue that what is the optimal topology for the purely distributed peer-to-peer (P2P).It is usually assumed that unstructured network will form a Power-Law topology.However,a Power-Law structure is not always the best for all the applications.In this paper,the influence of the overlay topology on P2P search is firstly investigated and the precise relation among the distribution of the degree,the query rate and the success rate is attained.Then an optimal distribution model of degrees in terms of the popularity of data items is proposed to guide the overlay construction.Finally,the experimental results show that the proposed topology is effective to improve the success rate for the Random Walks.The fundamental result is significant for the optimal overlay structure and offers a new understanding of the replica deployment in unstructured P2P.