Research On Load Balancing Algorithm Of Multi-controller SDN Network

In recent years,with the rapid development of the Internet,various new Internet applications have appeared one after another.At the same time,the computing functions and applications are gradually moved to cloud,and the traffic needed to be processed by the network is increasing.In this case,how to maximize the use of network resources is an urgent problem to be solved by the Internet technology.The cluster control method based on Software Defined Network(SDN)can effectively improve the resource utilization rate without changing the underlying hardware devices.But in the face of the huge amount of information,the controller in traditional SDN will possibly overload,resulting in unbalanced load.In order to solve the above problems,two dynamic load balancing algorithms are proposed based on the multi controller plane: the dynamic adaptive algorithm DAA based on the system averaging,and the distributed load balancing algorithm DGA based on the non-cooperative game.In the case of small network size and low network traffic,the DAA algorithm based on the principle of system averaging,requests the controller in the idle state to assign more loads in order to solve the problem of unbalanced load among the controllers.In the case of large network size and large network traffic,DGA algorithm is proposed.By transforming the switch migration process into the game process of the main controller role competition,it transforms the network utilization maximization problem to the game player's maximization of revenue.The area that participates in the same game activity is called Game-Playing Filed(GF).GF enables the parallel network game to be separated into independent games,making full use of the resources of each controller.Finally,the tests show that both DAA and DGA can achieve a certain load balancing effect and make full use of the control plane.DAA can effectively improve the resource utilization of controller cluster in smaller traffic network,and has higher throughput.DGA algorithm can effectively reduce the load of high load controller under the condition of large network traffic,and the response time of controller is reduced by fifty percent compared with DCP algorithm.