SDN中基于过程优化的动态负载均衡策略  

Dynamic Load Balancing Strategy Based on Process Optimization in SDN

作　　者：刘向举[1] 赵犇 方贤进[1] 徐杨洋 LIU Xiangju;ZHAO Ben;FANG Xianjin;XU Yangyang(School of Computer Science and Engineering,Anhui University of Science and Technology,Huainan 232001,Anhui,China)

机构地区：[1]安徽理工大学计算机科学与工程学院,安徽淮南232001

出　　处：《计算机工程》2023年第8期137-145,共9页Computer Engineering

基　　金：国家自然科学基金(61402012);安徽省重大科技专项(18030901025);安徽省属高校与人工智能研究院协同创新项目(GXXT-2021-006)。

摘　　要：在软件定义网络中,多控制器静态部署策略无法适应网络中流量动态变化,存在控制平面负载不均衡的问题。提出基于过程优化的动态负载均衡策略。通过优化原始的交换机迁移方案,以均衡各控制器负载作为目标,设计理想迁出流量和迁移交换机选取概率模型,选取待迁移交换机并确定迁入控制器。综合考虑时延与迁移代价对网络性能的影响,针对蚁群算法中收敛速度较慢且容易陷入局部最优的问题,通过对启发函数和信息素更新公式进行改进,并引入非线性递减挥发系数,为每个迁移交换机选取最佳的迁入控制器。为避免不同待迁移交换机选取同一个迁入控制器造成迁入控制器过载,通过设计交换机顺序迁移算法,实现交换机的协调迁移。仿真实验结果表明,与MUCS、NM、CDAA等策略相比,该策略在面对复杂的流量情景时,迁移交换机和迁入控制器的选取更加合理,在保证各控制器负载均衡的同时,迁移代价和流建立时间平均降低10.3%和36.1%,交换机与控制器之间时延平均降低13.6%。To address the issue of control plane load imbalance in Software Defined Network(SDN),where static deployment strategies for multiple controllers cannot adapt to dynamic changes in network traffic,a dynamic load balancing strategy based on process optimization is proposed.The original switch migration scheme is optimized as follows.To balance the load of each controller,ideal migration traffic is designed and a statistical model is selected for the migration switch.The switch to be migrated and the migration controller are thus determined.Considering the impact of delay and migration cost on network performance,improvements are made to the heuristic function and pheromone update formula in Ant Colony Optimization(ACO)algorithms.These improvements addressed the slow rate of convergence and tendency to fall into local optimization.Additionally,a nonlinear decreasing volatility coefficient is introduced to select the best migration controller for each migration switch.To avoid overloading the migration controller by selecting the same one for different switches,a switch sequential migration algorithm is designed to achieve coordinated migration of switches.The simulation results show that compared to MUCS,NM,CDAA dynamic load balancing strategies,the proposed strategy provides a more reasonable approach to selecting migration switches and migration controllers in complex traffic scenarios.It achieves a balanced load for each controller,reduces migration cost by an average of 10.3%,decreases flow setup time by an average of 36.1%,and reduces latency between switches and controllers by an average of 13.6%.

关 键 词：软件定义网络 多控制器 交换机迁移 负载均衡 过程优化 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]