Optimal leader selection for minimizing control traffic in distributed SDN controllers

Abstract

In distributed software-defined networking (SDN) environments, multiple controllers form a cluster while network states between controllers are synchronized by means of a consistency protocol. Meanwhile, a consistency protocol causes control traffic overhead as it enforces data accesses that originated from a controller to a specific network state partition to be redirected through networks to another controller who contains leader replica for the partition. In order to address the issue, we propose an optimal leader selection scheme that minimizes the control traffic caused by the data access redirections while preventing controllers from being overloaded. Preliminary simulation results show that the optimal leader selection scheme can achieve lower control traffic overhead than a load-based selection scheme.