Pratyaastha: an efficient elastic distributed SDN control plane

Several distributed SDN controller architectures have been proposed to mitigate the risks of overload and failure. However, since they statically assign switches to controller instances and store state in distributed data stores (which doubles flow setup latency), they hinder operators' ability to minimize both flow setup latency and controller resource consumption. To address this, we propose a novel approach for assigning SDN switches and partitions of SDN application state to distributed controller instances. We present a new way to partition SDN application state that considers the dependencies between application state and SDN switches. We then formally model the assignment problem as a variant of multi-dimensional bin packing and propose a practical heuristic to solve the problem with strict time constraints. Our preliminary evaluations show that our approach yields a 44% decrease in flow setup latency and a 42% reduction in controller operating costs.