A Synchronous Multi-Step Algorithm for Flexible and Efficient Virtual Network Reconfiguration

Reconfigurations of virtual networks in cloud environments are enabled by virtual machine (VM) migration technologies. A lot of research work has focused on the implementation of VM migration (such as pre/post-copy techniques) and the determination of the destination hosts for the VM placement. The latter is often related to virtual network embedding (VNE) because it entails the mapping of virtual network functions and traffic flows on the physical substrate. However, a lack of consideration of VNE in the research on VM migration (and vice versa) still prevails. We consider this joint problem and observe that when one regards this as a multi-step model, remarkable benefits in terms of migration time, migration traffic volume, and even migration feasibility are obtained. In this paper, we present a heuristic algorithm to accelerate the solution and show that high-quality solutions can be achieved in polynomial time with suitable parameter settings.