Learning the Optimal Synchronization Rates in Distributed SDN Control Architectures

Abstract

Since the early development of Software-Defined Network (SDN) technology, researchers have been concerned with the idea of physical distribution of the control plane to address scalability and reliability challenges of centralized designs. However, having multiple controllers managing the network while maintaining a "logically-centralized" network view brings additional challenges. One such challenge is how to coordinate the management decisions made by the controllers which is usually achieved by disseminating synchronization messages in a peer-to-peer manner. While there exist many architectures and protocols to ensure synchronized network views and drive coordination among controllers, there is no systematic methodology for deciding the optimal frequency (or rate) of message dissemination. In this paper, we fill this gap by introducing the SDN synchronization problem: how often to synchronize the network views for each controller pair. We consider two different objectives; first, the maximization of the number of controller pairs that are synchronized, and second, the maximization of the performance of applications of interest which may be affected by the synchronization rate. Using techniques from knapsack optimization and learning theory, we derive algorithms with provable performance guarantees for each objective. Evaluation results demonstrate significant benefits over baseline schemes that synchronize all controller pairs at equal rate.

Distributed Controller Placement in Software-Defined Networks with Consistency and Interoperability Problems

“…However, the greedy approach might not be suitable to optimize the makespan metric because of the controller to switch interaction rounds might be higher. So getting a logarithmic time algorithm to optimize the makespan might require some deep learning techniques as applied by Poularakis et al in [95][96][97] using some AI techniques like deep learning. On the other hand, capacity consistency for congestion freedom is stronger than connectivity consistency for loop freedom [66].…”

“…Even at that, the gap has not received the requisite attention from the research community to provide the needed interoperability. But lately, there have been some fruitful study attempts [60,[93][94][95][96][97][98][99][100][101][102][103][104][105]. And the existing solutions show variation across a range of performance metrics.…”

Software‐defined networking in vehicular networks: A survey

“…They proposed an algorithm to define optimal placement of SDN controllers with consideration of the intercontrollers synchronization overhead. In Reference 134, authors focused on the synchronization rates (ie, synchronization message dissemination frequency) among SDN controllers. In VANET, it is necessary to define properly the transmitted messages and the used protocols (ie, periodic or event based transmission) with considering the network conditions and the features of vehicular networks (eg, high mobility, density change over time).…”

Reinforcement and transfer learning for distributed analytics in fragmented software defined coalitions

“…The DAIS ITA team has addressed these challenges. For example, the fundamental understanding of controller synchronization has been studied in [1], while techniques for controller synchronization has been developed in [2], [3] and [4]. A hybrid control architecture for SDN and ad-hoc networks to combine the advantages of central and distributed control mechanisms is proposed in [5] and efficient techniques for sharing of coalition resources across domains in SDC are investigated in [6] and [7].…”