SDN中基于动态迁移优化的控制器负载均衡算法

Controller load balancing algorithm based on dynamic migration optimizing in SDN

为了改善软件定义网络(Software Defined Network,SDN)中由于流量突变引起的多控制器负载不均衡的问题,提出一种基于动态迁移优化(Dynamic Migration-Optimized Load Balancing,DMOLB)的控制器负载均衡算法。该算法在控制器负载阶段以常规控制器的负载作为过载的判断依据。选择迁移域阶段通过选出的迁入域减少交换机迁移的开销。在设定子域迁移度和有效期阶段基于选出的迁移域设定子域迁移度和交换机有效期,计算迁移交换机的数量,并在有效期内完成交换机协调迁移。仿真结果表明,与负载通告(Load Informing based Load Balancing,LILB)算法和阶段式控制器负载均衡(Stage Controller Load Balancing,SCLB)算法相比,该算法降低了交换机迁移通信开销,提高了控制器的资源利用率。

In order to solve the problem of unbalanced load of multiple controllers in software-defined network,a controller load balancing algorithm based on dynamic migration optimization(DMOLB)is proposed.In the controller load stage,the load of the conventional controller is taken as the judgment basis of overload.In the dynamic migration domain state,the overhead of switch migration is reduced through the selected migration domain.In the stage of setting sub-domain migration degree and validity period,set sub-domain migration degree and switch validity period based on the selected migration domain,calculate the number of migrated switches,and complete the coordinated migration of switches within the validity period.Simulation results show that,compared with the load informing based load balancing(LILB)algorithm,and the stage controller load balancing(SCLB)algorithm,the proposed algorithm reduces the communication overhead of switch migration and improves the resource utilization rate of controller.