Software-defined networking grants many advantages for networking via separating the control plane from the data plane. The Controller is the central and the single point of managing the whole network and responsible for decision-making in the SDN controller. However, using a single controller in the SDN model has a problem in reliability, scalability, and security which causes the SDN controller to be a single point of failure. This paper presents a structure which resolved this problem via building high availability controller (HAC) architecture for the control plane. OpenDayLight (ODL) controller was used as a point of study for making the clustering. D-ITG (Distributed Internet Traffic Generator) was used for benchmarking. It can perform and generate traffic at different layers and measure the important parameters that influence the network traffic and performance: Average delay, Average jitter, Average bitrate (Throughput), Packets dropped and others. Finally, we make a full comparison of the effects of these parameters on performance when using a single controller and a multi-controller.