Scalable OpenFlow Controller Redundancy Tackling Local and Global Recoveries

摘要

OpenFlow is expected to be an enabler that solves the problems of today's network. Thanks to the centralized management with OpenFlow, agile network operation can be achieved with flexible programmability; however, the centralized management implies a significant impact of any outages of the OpenFlow controller. Hence, a high availability technology is indispensable for building the OpenFlow controller, and the high availability system should consider extraordinary events (e.g., power outage) affecting the entire data center as well as anticipated server failures within a local system. In this paper, the high-availability of the OpenFlow controller is investigated, and a redundant method considering both local and global (i.e., inter data-center) recoveries is proposed by using the multiple-controllers functionality that is defined in OpenFlow switch specification version 1.2 and later. The proposed redundant scheme eliminates frontend server causing limitation of performance scalability, while it achieves competitive role change and failover times.