Research On Load Balancing Technology Based On SDN Controller Cluster

The development of big data,cloud computing and other new applications has put forward higher requirements for the flexibility and agility of computer network,while the traditional network is difficult to adapt to these requirements.Software Defined Networking(SDN)is a new type of network architecture.Its most prominent feature is the separation of forwarding and control.SDN has realized the centralization of control logic.However,with the continuous expansion of network scale,the single SDN controller structure will be faced with problems such as insufficient performance and single point failure.At present,the main method is to cluster multiple controllers into a distributed controller cluster.In the controller cluster architecture,the sudden data traffic may cause the load of a single controller to be too high,which reduces the network performance and even makes the controller paralyzed.Therefore,this paper mainly studies the load balancing technology based on SDN controller cluster.Firstly,based on the demand of load balancing in the SDN controller cluster scenario,this paper designs Dynamic Feedback Load Balancing(DFLB)algorithm.Based on the conditional trigger method,a new controller-to-switch mapping relationship is calculated according to the global load information of the cluster by DFLB algorithm.This algorithm can simultaneously migrate multiple switches of multiple overload controllers and reduce the load variance of the controller cluster rapidly.Compared with the fixed controller-to-switch mapping in the static deployment scheme,this algorithm can deal with the real-time changing network traffic more flexibly and improve the performance of the system.Secondly,this paper designs and implements a load balancing system based on SDN controller cluster.Each controller in the cluster has installed cluster management module,cluster synchronization module,load monitoring module,load balancing module and switch migration module.The system periodically collects the load information of the cluster and determines whether to carry out the load balancing process.When the cluster load is uneven,the system runs the DFLB algorithm,generates the switch migration list and completes the smooth migration of the switchs.Finally,the designed load balancing system was actually deployed based on Mininet simulation tool and Floodlight controller.The experiments prove that the system can effectively balance the load of SDN controller cluster through the efficient migration of switches,reduce the response delay while improving the throughput of the system,and finally improve the overall performance of the network.This system is helpful for the large-scale deployment of SDN controller cluster.