Dynamic application load balancing in distributed SDN controller

To deploy Software-Defined Networking (SDN) in a large-scale network, cluster-based distributed SDN controllers were proposed, which enable performance scaling by simply adding a new server in the cluster. However, loads caused by many control messages from many kinds of SDN applications have not been widely studied so far. In this paper, we show an architecture of a distributed SDN controller where all kinds of applications are running on all of the servers to share the loads caused by the applications. We propose a dynamic application load balancing method which calculates the weight of round robin scheduling of an external load balancer to distribute requests submitted to the applications among the servers. Experimental results show the method increases the performance of the controller by reducing inter-server messages.