Dynamic Switch Migration in Distributed Software-Defined Networks to Achieve Controller Load Balance

• Published in: IEEE journal on selected areas in communications Vol. 37; no. 3; pp. 515 - 529
• Main Authors: Xu, Yang, Cello, Marco, Wang, I-Chih, Walid, Anwar, Wilfong, Gordon, Wen, Charles H.-P., Marchese, Mario, Chao, H. Jonathan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Blackout; Computational modeling; Computer simulation; Controllers; Disruption; distributed controllers; Load balancing; Load distribution (forces); Load management; Load modeling; Mapping; Migration; Network reliability; Process control; Silicon; Software reliability; Software-defined networking; Source code; Stress concentration; switch migration; Switches; Switching theory; Traffic management
• ISSN: 0733-8716; 1558-0008
• DOI: 10.1109/JSAC.2019.2894237

Multiple distributed controllers have been used in software-defined networks (SDNs) to improve scalability and reliability, where each controller manages one static partition of the network. In this paper, we show that dynamic mapping between switches and controllers can improve efficiency in managing traffic load variations. In particular, we propose balanced controller (BalCon) and BalConPlus, two SDN switch migration schemes to achieve load balance among SDN controllers with small migration cost. BalCon is suitable for the scenarios where the network does not require a serial processing of switch requests. For other scenarios, BalConPlus is more suitable, as it is immune to the switch migration blackout and does not cause any service disruption. Simulations demonstrate that BalCon and BalConPlus significantly reduce the load imbalance among SDN controllers by migrating only a small number of switches with low computation overhead. We also build a prototype testbed based on the open-source SDN framework RYU to verify the practicality and effectiveness of BalCon and BalConPlus. Experiment confirms the results of the simulations. It also shows that BalConPlus is immune to switch migration blackout, an adverse effect in the baseline BalCon.