【作者】 曾宇光；

【导师】 陈志刚；

【作者基本信息】 中南大学 ， 计算机应用技术， 2007， 硕士

【摘要】 对等网应用在近几年内已得到突飞猛进的发展。资源共享系统是对等网最重要的应用之一。资源系统的性能极大地取决于P2P系统中的一个核心问题：如何高效地定位到所需要的资源，即路由算法问题。P2P覆盖网为一系列可扩展和非集中式分布应用提供了一个新颖的平台。在结构化P2P网络中，物理网络和覆盖网之间的唯一联系是分布式哈希表，节点里没有包含任何关于其物理位置的信息。这样构建而成的P2P未能充分利用底层物理网络的拓扑结构，从而造成实际的路由效率低下。因为路由算法是P2P的核心。本文围绕P2P路由效率的改善，对如何提取节点在物理网络上的位置信息和如何利用位置信息构造拓扑敏感的P2P系统进行了深入的研究，提出了利用网络拓扑结构来改进P2P路由性能的方案，并通过实验和分析阐明了此方案能有效地改善现有P2P路由效率。JXTA是Sun公司提出的一个构建P2P环境的平台，提供在任何平台、任何地方以及任何时间实现P2P计算的一整套简单、小巧和灵活的机制。但是随着网络节点的不断增多，网络规模的不断扩大，其所采用的“洪泛”路由机制造成网络流量急剧增加，从而导致网络中部分低宽带节点因网络资源过载而失效，致使路由效率低下。本文找出使用了汇集节点视图是导致效率低下的原因，提出了将DHT引入JXTA的方案，最后给出了方案的设计与实现。更多还原

【Abstract】 Application of P2P(Peer-to-Peer)network has developed rapidly in recent years. Resource sharing system is an important application of P2P. The performance of such system depends on the kernel problems of P2P: how to locate the needed resource effectively, that is, routing algorithm.P2P overlay network offers a novel platform for a variety of scalable and decentralized, distributed applications. In a structured P2P network, the only relation between physical layer and overlay network is DHT and nodes do not contain any information about their physical location. Such P2P overlay network does not take into account physical network topology and results in high routing latency and low efficiency. Focusing on improving routing enhancement, the thesis conducts an in-depth research on how to extract topology information and how to utilize the information to construct topology-aware P2P systems. The thesis proposes the solution exploiting the network topology and proves the solution can greatly improve routing efficiency in Chord.JXTA is a platform proposed by Sun to construct P2P environment, and provides a simple, small and flexible mechanics to realize P2P computing at any platform, any place and any time. However, with the increase of network nodes and enlargement of network scale, its "flooding" routing algorithm leads to rapid augmentation of network flow, and results in the low latency. The thesis finds out that employing rendezvous peer view is the reason of that, and proposes the solution to introduce the DHT into JXTA. The design and implementation of the solution are given at last.更多还原