导　　师： 俞能海

学科专业： H1002

授予学位： 硕士

作　　者： ;

机构地区： 中国科学技术大学

摘　　要： 云计算是2007年底正式提出的一个新的概念，它可以说是一个革命性的创新，意味着计算能力也可以作为一种商品进行流通，就像煤气、水电一样，取用方便，费用低廉，不同之处只是在于它是使用互联网进行传输的。至今为止，google、microsoft、ibm、亚马逊等it商业巨头都推出了自己的云计算平台，并把云计算作为其未来发展的最主要战略之一。因此，云计算的研究不但紧跟业界技术发展的趋势，同时还具有较高的应用价值。 在云计算系统的后端，有成千上万的服务器，如何有效组织如此大量的服务器是云计算系统高效稳定运行关键问题之一。一个合理的网络拓扑不但可以提高网络的性能，而且能够保证网络的稳定性，使网络在部分节点或链路故障或拥挤时也能正常工作。云计算系统后端的网络拓扑特性有别于一般的网络拓扑，需要我们重新考虑和研究。 hadoop是一个在集群上运行大型数据库处理应用程序的开放式源代码框架。它支持通过google的mapreduce编程范例来创建并执行的应用程序，在很多大型网站上都已经得到了应用，可以说是目前最为广泛应用的开源云计算软件平台，但其发展时间较短，研究还不够深入，还有较多值得改进的地方。 本文主要研究工作和贡献如下： 1.通过调研云计算的网络需求，分析云计算的网络拓扑结构特点，提出云计算网络拓扑结构应该由中心的主干交换部分和外围的树状子网组成的基本构想；利用图论和最优化理论，基于贪心算法思想，针对其主干交换网络的拓扑设计，提出了自动拓扑设计算法rga并仿真实现。实验结果表明，与已有算法比较，所提出算法更为有效。 2.通过调研hadoop的相关资料，在实验室搭建配置了8台pc组成的hadoop平台；对hadoop的mapreduce工作模式进行分析，针对它的� As a new concept proposed in the end of 2007, cloud computing is a great revolution in the IT field. It means that computing can be used as a commodity, likes coal gas or electricity. The only difference between them is that cloud computing transports by the computer networks. Up to now,Google、Microsoft、IBM、Amazon and some other famous cooperation has proposed their cloud computing application, and take cloud computing as one of the most important stratage in the future. In the back end of could computing system, there are thousands of servers. How to organize these servers is an important problem to guarantee high performance of the cloud computing system. A reasonable network topology can not only improve the performance of networking, but also enhance the stability of the system and make it works when some nodes or links failed. The could computing system’s network topology is different from the typical internet, so it need to be reconsidered. Hadoop is an open source code frame for very large data process application, which runs on a cluster of commercial PCs. It create pallrall program through Google’s MapReduce method and areadly been used by many famous IT company. Hadoop can be taken as the most popular open source could computing software, but there are many points to be improved since it is a young program. Based on the analyse above, this thesis research on the follow two issues of cloud computing: 1. We surveyed the requirement of cloud computing’s networking; analyzed the architecture of cloud computing’s networking topology, and thought that the networking topology should be composing of two parts: the center switch trunk and some tree shape branch subnet. Then we proposed the Reversed Greedy Algorithm /(RGA/) for the center switch trunk’s topology design, based on the graph theory, optimization theory and classic greedy algorithm. Finally we do some experiments and comparison to verify the algorithm’s usability and advantages. 2. We survey a lot of re

关 键 词： 云计算 网络拓扑 计算能力 网络性能 数据库处理 开放式源代码 加权轮询算法

领　　域： [自动化与计算机技术] [自动化与计算机技术] [自动化与计算机技术] [自动化与计算机技术]