A Declarative Failure Recovery System in Software Defined Networks

Different services have different requirements in failure recovery. However, in the current network, the failure recovery schemes generally handle all the traffics in the same manner, which is inefficient. Software Defined Networking (SDN) enhances network flexibility by centralized control of traffics and resources. In this paper, we develop a Declarative Failure Recovery System (DFRS) for customized failure recovery based on SDN, which aims to guarantee the transmission quality during failure with limited memory overhead. First, we propose an algorithm to find the safe point satisfying the recovery demands and construct the backup path accordingly. Second, as the switch memory is limited, it is a challenge to find the optimal solution that allocates backup rules to the corresponding switches (proved to be NP-complete). Then, we design two algorithms (ADD and SUB) to solve this problem, which minimize the total number of allocated backup rules with the network resource constraints and recovery goal enforcement. Simulation results on real topologies show that compared with failure protection, DFRS can achieve flexible failure recovery and save around 95 percent switch memory space to achieve the same goal.