Control-Plane based Failure Detection for Highly Available Software-Defined Network

To ensure high availability, redundancies such as active/standby controllers have been adopted on production SDN networks. However, the complex functionalities embodied by a SDN network make it difficult to ascertain the presence of failures. Not all failures will exhibit as component crashes to be captured by heartbeat-based failure detectors. We propose a novel failure detector for SDN network based on transparent monitoring of control-plane messages and real-time modeling of network state. By detecting deviation of the model, the proposed failure detector is capable of detecting a wide range of failures. The detector does not depend on specific SDN applications or controllers. We implemented a prototype for OpenFlow-based [3] SDN network and provide the preliminary results confirming the feasibility of a control-plane based failure detector.