A Load Informing Based Load Balancing Mechanism for Multiple Controllers in SDN

Load balancing of multiple controllers is currently a focused issue in the research area of Software Defined Networking (SDN) deployment. Considering the issue of time efficiency of load balancing, this paper proposes a Load Balancing mechanism based on a Load Informing strategy (LILB). The mechanism involves four components: load measurement, load informing, balance decision and switch migration. Due to the function of load informing component, when a controller becomes overloaded, it can make load balance decisions without collecting other controllers load information. To reduce the communication overload and processing overhead caused by load informing component, this paper also proposes an inhibition algorithm to lower the frequency of informing load information. Moreover, this paper designs some decision methods of judging overloaded controllers, migrated switches, target controllers, and a judge about accepting a migration request for target controllers to avoid the load oscillation among controllers. Meanwhile, to achieve the smooth switching of controllers roles during migrating switches, an information interaction procedure is also designed. Finally, experiments are carried out based on Floodlight and Mininet to verify the feasibility and efficiency of the proposed mechanism.