【作者】 孙静；

【导师】 李智勇； 刘宏立；

【作者基本信息】 湖南大学 ， 计算机技术（专业学位）， 2013， 硕士

【摘要】 计算机对等网络技术(P2P技术)是目前计算机网络技术领域的研究热点之一,它受到广泛关注的原因在于其能充分利用互联网的通信、存储、服务等计算能力,实现资源共享。为了充分利用P2P网络资源,必须设计良好的资源发现机制,以实现在P2P网络中对各类资源信息的高效搜索。国际上几个研究小组独立地提出了 Chord、CAN、Pastry、Tapestry等DHT结构的P2P系统解决方案,其中Chord算法具有负载平衡、分布性好、可扩展性强,较高的灵活性等优点,但也存在一些不足。其中最显著的不足是Chord在设计时忽略了参与节点在物理网络上的邻近性,导致重叠网络和物理网络脱节,从而造成实际的路由效率低下,改进Chord算法具有重要的研究意义。本文对P2P网络系统及Chord算法进行深入的研究与分析,提出了针对Chord算法的优化和改进策略,并对算法的有效性、可用性等进行了仿真实验和分析。论文的主要工作如下:(1)在深入分析P2P网络搜索方法的基础上,以DHT(Distributed Hash Table,分布式哈希表)中的Chord算法为切入点,针对参与节点在物理网络上的邻近性以及节点路由表的优化改进,提出了一种改进的Chord算法,理论分析表明改进优化是合理的。(2)针对改进后的Chord算法进行了仿真实验和分析,实验结果表明改进后的Chord算法能有效提高P2P网络资源发现与搜索能力。(3)设计并实现了基于改进后的Chord算法的XML文档查询模型,它可以将用户输入的XML文档存储到系统中;同时对于XML查询也可以通过查询P2P各个Peer节点返回用户所需的XML数据。更多还原

【Abstract】 Computer peer-to-peer(P2P)network technology is currently one of the hot research topic in the field of computer network technology.In order to realize the sharing of resources,it can make full use of Internet communication,storage,service etc.So,it has been widely concerned.In order to make full use of the P2P network resources,to achieve efficient for all kinds of resources in the P2P network information search,it must design a good resource discovery mechanism.Several international research groups independently proposed solution of P2P system with DHT structure,such as the Chord,CAN,Pastry,Tapestry etc.The Chord algorithm has a good load balance,distribution,scalability,high flexibility and other advantages,but there are also some shortcomings.The most significant disadvantages of the Chord algorithm is that its design ignores the proximity of participating nodes on the physical network.So,it led to the overlap and physical network disconnect,and therefore the actual routing inefficiencies.So,the improved Chord algorithm has important research significance.This paper makes a deep research and analysis on P2P network system and DHT algorithm.It puts forward the optimization and improvement strategy of Chord algorithm,and it has carried on the simulation experiment and analysis to the effectiveness and feasibility of the algorith.Paper main work is as follows:(1)On the basis of in-depth analysis of P2P search method,Chord algorithm in DHT(Distributed Hash Table)as the breakthrough point,according to proximity in physical network and optimization of node routirg table,the parer presents an improved Chord algorithm.And theoretical analysis indicates that the improved optimization is reasonable.(2)According to the improved Chord algorithm,mading a simulation and analysis,the experimental results show that the improved Chord algorithm can effectively improve the discovery and search capabilities of P2P network resource.(3)Designed and implemented XML Document the query model of based on the improved Chord algorithm,that can store XML documents by the user enter into the system.At the same time for the XML query,it also can query the each Peer node of P2P,to return the XML data according to user’s requirements.更多还原