【摘要】 可编程性恢复是软件定义广域网（Software Defined Wide Area Network, SD-WAN）中节点失效后保障网络服务质量的有效方法 .针对可编程性恢复中失效节点形式单一的问题，提出一种基于启发式算法的主备份控制器部署方法来确保交换机和控制器失效时网络的可编程性.在主控制器部署时，利用控制路径密度和强度衡量域内控制路径的可靠性，提升交换机故障情况下的路径可编程性；在备份控制器部署时，将一定数量的、相邻的主控制域划分为多个备份区域，在备份区域中部署一个备份控制器，建立它与交换机的映射策略，使脱机交换机以及离线流的恢复能力最大化，以提升控制器故障情况下的离线流的可编程性.此外，重新定义狼群算法的智能行为，提出一种离散狼群算法解决主备控制器的部署问题.在四种真实网络拓扑上进行实验，结果表明提出的方法在交换机故障的情况下能降低失效控制路径的影响，在控制器故障时能最大程度上恢复离线流.更多还原

【Abstract】 Programmability recovery is an effective method to ensure network quality of service after node failure in Software Defined Wide Area Network(SD-WAN). To address the problem of a single form of failed node in programmability recovery,a heuristic algorithm-based primary backup controller deployment method is proposed to ensure network programmability when switches and controllers fail. When deploying primary controllers,control path reliability in the domain is measured by control path density and strength to improve path programmability in the event of switch failure. When deploying backup controllers,a certain number of adjacent primary control domains are divided into multiple backup regions,and a backup controller is deployed in these regions to establish their mapping to switches. This aim is to maximize the recoverability of offline switches and offline flows to improve the programmability of offline flows in the event of controller failure. Further,a discrete Wolf Pack algorithm with redefined intelligent behaviors is presented to tackle the placement problem of the primary and backup controllers. Experiments are conducted on four real-world network topologies,and the results show that the proposed method can reduce the impact of failed control paths in the case of switch failure and maximize the recovery of offline flows in the case of controller failure.更多还原