Due to the dynamic nature of traffic, networks must rapidly adapt to changing conditions. This is especially true in the context of the control plane which must ensure continuous and seamless operation. Switch migration, the process of changing the controller associated with a switch, is an important tool in facilitating this goal. In this work, we study the problem of minimizing the overall time to migrate a set of switches. We examine the problem subject to constraints on controller resources and QoS groups. We show that the problem is NP-hard and provide heuristic algorithms for solving large instances in practice. Through extensive experiments, we demonstrate that the heuristics achieve performance close to optimal while reducing the running time by several orders of magnitude.

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.

Load migration is essential in any distributed SDN control platform due to natural load imbalance and dynamic nature of input traffic. Existing solutions focus on migrating a single switch between two controller instances. Migrating multiple switches requires careful planning due to controller resource constraints, and to ensure minimum service interruption in the network. In this poster, we present a model and a solution for migration scheduling, taking a set of switch migrations as input, generating a migration schedule with respect to controller resource and service interruption constraints.

The dynamic nature of network traffic can lead to load imbalance amongst controller instances in a distributed SDN controller. A highly loaded controller instance can be slower in responding to datapath queries, and can slow down the entire control platform. In this poster, we present a new and efficient load migration protocol for shifting input load associated with overloaded controller instances towards lightly loaded instances. Unlike existing protocols for load migration, our protocol ensures consistency among controller instances, and can handle failures during migration procedure. Our protocol reduces the migration time by 20-55%, and the migration buffer size by 10-15%.