基于SDN的负载均衡网络控制器算法

SDN-based Network Controller Algorithm for Load Balancing

当前网络新兴科技呈井喷式发展势头,这些新兴科技在为人们的生活带来极大便利与乐趣的同时,对网络处理海量数据并兼顾安全性和稳定性也提出了更高的要求。一方面,传统网络架构的处理能力很难满足该要求;另一方面,为获得更高的网络效益而开展流量调度优化的研究也大多停留在链路模块,缺少对服务器模块的关注。在此基础上,针对目前绝大多数流量调度优化算法所存在的不足,提出了额外增加了对服务器模块进行考量的路径-服务器流量调度(Path-Server Traffic Scheduling,PSTS)算法,并基于软件定义网络(Software Defined Network,SDN)范式利用Ryu控制器进行模块化功能实现。实现过程中,通过对链路层面和服务器层面的影响因子(性能指标)进行度量,并引入之前已获取的影响因子信息计算权重,来实现对每条链路和每个服务器的排序和筛选,为最终的最佳流量调度提供支撑。仿真结果表明,在流量负载相同的情况下,相较于目前广泛接受的动态负载均衡(Dynamic Load Balancing,DLB)算法,所提出的PSTS算法可以实现更高的平均带宽利用率和更低的平均传输时延;同时,在负载均衡方面,当网络中有大量数据流时,PSTS算法可以更为有效地将数据流均衡地分配给各个服务器,极大地避免了网络中局部拥塞情况的发生,提高了数据流的处理速度,进而提升了网络的整体性能。

Currently,the emerging technologies of network show the booming development trend,which bring great convenience and fun for people’s life.However,they put forward the newer and higher requirements for efficient processing ofbig data withdesired security and reliability.On the one hand,the processing ability of the traditional network is difficult to meet these performance and security requirements;on the other hand,in order to obtain higher network benefits,researches of traffic scheduling optimization almost focuse on considering the link module factor,lacking the consideration of server module.In this paper,aiming at the shortcomings of current existing traffic scheduling optimization algorithms,an optimization algorithm called PSTS(Path-Server Traffic Scheduling)which introduces the additional consideration of server module was proposed.The PSTS algorithm is based on the SDN(Software Defined Network)paradigm and finished the modular function realization by using the Ryu controller.In the implementation process,by means of measuring the impact factors(performance metrics)of link and server levels and introducing impact factors which are obtained previously,the proposed algorithm realizes the sorting and filtering operations on each link and each server by calculating the weights.Meanwhile,the sorting and filtering results providestrong support for the final optimal traffic scheduling.The simulation results show that PSTS algorithm can achieve higher average bandwidth utilization and lower average transmission delay compared with DLB(Dynamic Load Balancing)algorithm when they have the same traffic load.At the same time,the proposed algorithm can effectively distribute the data stream more balanced to each serverwhen the network has a large number of data streams,which indicates that it can avoid the local congestion of network significantly,improve the processing speed of data stream,andfinally enhance the overall performance of the network.