An experimental investigation of SDN controller live migration in virtual data centers

Abstract

Virtual data centers (VDCs) are among competitive advantages offered to businesses by cloud computing. Through VDCs, organizations can use a pool of on-demand virtual infrastructures in the form of a data center without paying the up-front costs of an actual data center. With the advent of software-defined networks (SDNs), it is now possible to provide the VDC's tenants with overlay SDNs to cover their diverse networking needs. However, live virtual machine (VM) migration, which is a technique in data centers to address issues such as load balancing, imminent server failure, and host maintenance can require parts of or an entire overlay SDN to be migrated to a different host. This introduces challenges which need to be addressed. Otherwise, the services running on the overlay SDNs will get interrupted which may lead to a low quality of end user experience (QoE) as well as a violation of service level agreements (SLAs) by the cloud service providers. Investigating SDN controller live migration in a virtual data center needs a testbed which brings into account cloud, SDN, VM migration, and overlay networks, to name a few. This paper introduces such a testbed and investigates SDN controller live migration in a virtual data center. It identifies container size, traffic volume, traffic pattern and transport layer protocol throughput as contributing factors of a successful SDN controller live migration. It then clarifies how these factors may affect a live migration process in terms of migration time and down time through conducting experiments on a state-of-the-art cloud data center testbed.