Load Migration in Distributed SDN Controllers
Mohammad Amin Beiruti, Yashar Ganjali · 2020
Distributed control solutions were introduced to address controller reliability and scalability issues in Software-Defined Networking (SDN). The dynamic nature of network traffic can lead to load imbalance amongst controller instances. A highly loaded controller instance can be slower in responding to datapath queries, and can slow down the entire control platform as state synchronization, and consensus amongst controller instances are performed cooperatively.In this paper, we present a new and efficient load migration protocol, called ERC, for shifting input load associated with overloaded controller instances towards lightly loaded instances. Our protocol has three distinguishing properties compared to prior works on this area: it is extremely efficient, resilient to failures during migration, and ensures consistency among all controller instances. ERC can be used for a wide range of network applications including load balancing, power saving, and resource optimization. It is also significantly more efficient than existing load migration protocols with 25-55% reduction in migration time, and 10-20% reduction in required migration buffer size.