第 40卷 第 12期
2018年12月
电
子
与
信
息
学
报
Vol. 40No. 12
Dec. 2018
Journal of Electronics & Information Technology
基于软件定义网络的服务器集群负载均衡技术研究
于天放*
芮兰兰
邱雪松
(北京邮电大学 网络与交换技术国家重点实验室 北京 100876)
摘 要:在当前的网络体系结构下,采用硬件系统实现服务器集群负载均衡存在着获取负载节点状态困难、流量
导向方式复杂等制约因素,不利于提升服务器集群的伸缩性和服务性能。针对此问题,该文提出一种基于软件定
义网络(SDN)的负载均衡机制(SDNLB)。该机制借助SDN具有的集中式控制和流量灵活调度优势,利用SNMP协
议和OpenFlow协议对服务器的运行状态和全局网络负载信息进行实时监测,并通过权值计算的方式选择出权重
最高的服务器作为流处理的目标服务器,在此基础上,采用最优转发路径算法进行流量调度,从而达到提高服务
器集群的利用率与处理性能的目的。搭建了实验平台对SDNLB的性能进行仿真测试,实验结果表明:在相同的
网络负载条件下,SDNLB与其他负载均衡算法相比,能够有效地降低服务器集群的负载,并能够显著提高网络
吞吐量和带宽利用率,缩短流的完成时间和平均时延。
关键词:软件定义网络;OpenFlow;服务器集群;负载均衡;流量工程
中图分类号:TP393
文献标识码:A
文章编号:1009-5896(2018)12-3028-08
DOI: 10.11999/JEIT180207
Research on SDN-based Load Balancing Technology of Server Cluster
YU Tianfang
RUI Lanlan
QIU Xuesong
(State Key Laboratory of Networking and Switching Technology, Beijing University of
Posts and Telecommunications, Beijing 100876, China)
Abstract: Under the present network architecture, it is disadvantageous for scalability and service performance
of server cluster to adopt hardware systems to realize load balancing of server cluster, because there are some
restriction factors in such a method, including the difficulty of acquiring load nodes status and the complexity
of redirecting traffic, etc. To solve the problem, a Load Balancing mechanism based on Software-Defined
Networking (SDNLB) is proposed. With superiorities of SDN such as centralized control and flexible traffic
scheduling, SDNLB monitors run states of servers and overall network load information by means of SNMP
protocol and OpenFlow protocol in real time, and chooses the highest weight server as target server aiming for
processing coming flows through the way of weight value calculation. On this basis, SDNLB takes full
advantage of the optimal forwarding path algorithm to carry on traffic scheduling, and achieves the goal that
raises utilization rate and processing performance of server cluster. An experiment platform is built to carry out
simulation tests for overall performance of SDNLB, and the experiment results show that under the same
network load conditions, SDNLB lowers effectively loads of server cluster, noticeably raises network throughput
and bandwidth utilization, and reduces finish time and average latency of flows, compared with other load
balancing algorithms.
Key words: Software-Defined Networking (SDN); OpenFlow; Server cluster; Load balancing; Traffic engineering
1 引言
的方式来负载多用户的接入和任务请求,并借助专
用的负载均衡器将系统负载分配到不同的节点进行
处理,避免服务器出现单点故障造成流量的损失。
负载均衡器所采用的调度算法是影响负载均衡效果
的关键因素。一般而言,负载均衡算法主要分为无
状态算法和有状态算法。较典型的无状态算法包括
轮询调度算法RR[1]、目标地址散列算法DH[2]等。
这些算法具有实现简单、易于部署的特点,在执行
随着云计算、大数据等新兴技术的不断涌现,
数据中心等大型机构通常采用多台服务器组成集群
收稿日期:2018-02-28;改回日期:2018-08-13;网络出版:2018-08-22
*通信作者: 于天放ꢀ
基金项目:国家自然科学基金(61702048, 61302078)
Foundation Items: The National Natural Science Foundation of
China (61702048, 61302078)
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