基于SDN数据中心的链路负载均衡研究和实现

发布时间：2019-03-04 14:31

【摘要】：近十年来,我国的互联网行业发展迅猛。面对如此庞大的网络数据流量,和各种各样的新型网络业务应用,传统的以TCP/IP为核心的网络架构越来越表现出其扩展复杂和难以维护等各种劣势,这也促使着人们对新一代网络架构的研究。正如手机应用开发兴起,人们想要将未来网络改造成能像手机应用一样自由实现各种功能的软件模式,于是SDN(Software Defined Networking)的思想产生了。在SDN的概念中,关键思想是网络数据的控制和转发分离。而另一方面,随着互联网的广泛应用,加之移动网络、物联网、大数据和云计算等新网络技术的产生和发展,为了处理如此海量规模的数据,数据中心应运而生。数据中心一般是由一个研究机构、单位或企业搭建并集中控制管理,跟SDN集中控制的思想几乎完全契合,因此SDN在当前环境下最主要的应用场景或者说现实应用需求都在数据中心。数据中心的核心价值就是可以将成千上万的数据集中处理,所以对网络的性能要求极高,这对数据中心内部的流量负载均衡提出了严格要求。本文的目的是研究如何在SDN数据中心实现链路负载均衡。本文针对SDN数据中心网络东西向流量的稳定性,提出了基于流量探测的动态负载均衡算法,简称为DLB(Dynamic load balance)算法。该方法的基本思想是根据探测流的变化情况,把流分为稳定流和非稳定流。对于非稳定流,采用ECMP(equal cost multipath)算法进行转发;对于稳定流,使用DLB算法中的流路由算法来找到一条最优固定路径来快速稳定地转发,当链路开始阻塞时,流路由算法会对较大的稳定流进行源端虚拟机迁移,以达到避免稳定流过于集中化,均衡数据中心网络负载的目的。同时,为了测试DLB算法的性能,我们设计并搭建了SDN的数据中心实验平台,并在平台上实现了负载均衡应用来测试算法性能。通过跟其他算法的对比测试,实验结果表明,在网络中稳定流比例越高时,同等吞吐量下DLB算法能达到比ECMP和其他对比算法更好的优化性能。
[Abstract]:In recent ten years, the Internet industry of our country develops rapidly. In the face of such a huge network data flow, and a variety of new network business applications, the traditional network architecture with TCP/IP as the core shows more and more disadvantages such as complexity of expansion and difficulty to maintain. This also prompted people to study the new generation network architecture. Just as mobile application development has sprung up, people want to transform the future network into a software model that can perform all kinds of functions as freely as mobile applications, so the idea of SDN (Software Defined Networking) has come into being. In the concept of SDN, the key idea is the separation of network data control and forwarding. On the other hand, with the wide application of the Internet, together with the emergence and development of new network technologies, such as mobile network, Internet of things, big data and cloud computing, data center emerges as the times require in order to deal with such large-scale data. A data center is typically built by a research institution, unit, or enterprise and centrally controlled and managed, almost entirely in line with the idea of SDN centralized control. Therefore, the most important application scenarios or real application requirements of SDN in the current environment are in the data center. The core value of the data center is that it can process thousands of data centrally, so the performance of the network is very high, which puts forward strict requirements for the load balancing of traffic in the data center. The purpose of this paper is to study how to achieve link load balancing in SDN data center. Aiming at the stability of east-west traffic in SDN data center network, a dynamic load balancing algorithm based on traffic detection is proposed in this paper, which is called DLB (Dynamic load balance) algorithm for short. The basic idea of this method is to divide the flow into steady flow and unsteady flow according to the change of probe flow. The ECMP (equal cost multipath) algorithm is used to forward the unsteady flow. For stable flow, the flow routing algorithm of DLB algorithm is used to find an optimal fixed path for fast and stable forwarding. When the link starts to block, the flow routing algorithm will migrate the source-end virtual machine to the larger stable flow. In order to avoid over-centralization of steady flow and balance the load of data center network. At the same time, in order to test the performance of DLB algorithm, we design and build the data center experimental platform of SDN, and implement the load balancing application to test the performance of the algorithm on the platform. Compared with other algorithms, the experimental results show that the higher the proportion of steady flow in the network, the better the performance of DLB algorithm under the same throughput than that of ECMP and other algorithms.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP308

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