【作者】 曲磊；

【导师】 杨放春；

【作者基本信息】 北京邮电大学 ， 计算机科学与技术， 2011， 博士

【摘要】 目前互联网中的数据信息资源分布在各个独立的节点上,如何高效、快速地索引、查找、定位以及访问这些资源是一个需要关注的重要问题。随着计算机网络的发展和计算机性能的提高,以维护全局状态为基础的一跳路由机制在资源的发现和定位方面显出特有的优势,正越来越受到关注和研究。基于对现有的应用一跳路由机制的资源定位和发现方法的分析,本文认为,目前的一跳路由机制在资源的定位和发现方面仍有众多的问题尚未得到关注及有效解决,尤其是涉及到更新消息分发拓扑结构、错误控制以及适用网络规模方面的问题。因此,本文对基于一跳路由机制的资源的定位和发现方法中一系列关键问题进行了深入研究,取得如下成果：1.提出了一跳路由机制中利用节点空闲资源来提高分发效率的算法。本研究点从节点的网络能力出发,充分利用网络中节点的空闲资源,改进一跳路由机制的分发拓扑,使节点能够实时的动态调整更新消息的分发任务负载。有效的提高了更新消息的分发效率,并实现了异构节点的负载均衡。2.分析了一跳路由机制中拓扑错误对系统的影响问题,进而提出了相应的错误检测算法。本研究点针对由于一跳路由机制中资源的路由信息和拓扑的维护信息记录在同一个表内,导致系统拓扑信息发生错误及错误的积累不能够被及时感知和修正致使系统发生崩溃的问题进行了分析,在此基础上提出了针对目前基于树状分发拓扑结构的错误检测算法,使得应用一跳路由机制的系统中产生的错误能够被及时被发现和修正。3.针对一跳路由机制因系统维护开销过大而不适合于大规模网络的问题,提出了一种采用消息融合机制来减少系统网络开销的算法。本研究点从系统实现角度出发,使用消息融合机制,合并同路径更新消息来减少系统的维护开销,实现了消息更新过程中的资源开销优化。更多还原

【Abstract】 Nowadays, the internet resources are separately distributed in different peers. How to index, locate and access these data resource quickly and efficiently is a concerned issue. And with the development of computer networks and performances, the one-hop routing mechanism which maintains the global state of all peers shows great advantages in resources discovery and location, so it attracts more and more attention and study.According to analysis of current one-hop routing mechanisms, we find that the dissemination topology for updating messages and the system maintenance overhead is the mainly referred aspect. But there are still lots of problems which have not been resolved or even concerned. Based on current one-hop routing optimization methods, we address several critical problems. The contribution of this dissertation includes:1. Proposed an algorithm that improves the topology dissemination performance by using the idle resources in peers. This algorithm improves the dissemination topology for one-hop mechanism, makes peers building dissemination trees based on peers’real-time network environments and resources dynamically. With these enhancements, the algorithm improves the dissemination performance of updating messages and achieves loading balance in different peers.2. Analyzed the topology dissemination errors in one-hop routing mechanisms and further proposed a topology errors detection and recovery schema. We analyzed the characteristics of the system errors and proposed the errors detection method for the tree topology. The simulation shows that the schema can identify and fix topology errors, and also reduces the system maintenance overhead.3. Each peer in one-hop routing mechanisms has to maintain a big routing table, making it unsuitable for large networks due to the upsurge of the traffic maintenance with inflation of network scale. To fill this gap, we proposed a message-merging mechanism to reduce the maintenance consumption. We studied the messages dissemination structure and introduced the traffic reduction schema by merging the same route messages into one. Furthermore, the approach is evaluated in the simulation and the result shows good experimental performance.更多还原