NICE: Network-Aware VM Consolidation Scheme for Energy Conservation in Data Centers

Energy conservation and network performance have become two of the most important issues in data center as the scale of cloud services continues growing. Recent researches usually consider these two issues separately. Energy conservation mainly deals with hosts, which reduces total energy consumption by consolidating virtual machine(VM)s to fewer hosts, and network performance mainly deals with network scalability and energy efficiency, which improves data center network(DCN) scalability by applying new network topologies or routing schemes and improves DCN energy efficiency by consolidating traffic. In this paper. we jointly consider these two) issues and define Combined VM Consolidation (CVC) problem. We prove that CVC is NP-complete and is inapproximable by a factor of 3/2 epsilon unless P = NP. Next, we propose NICE: Network-aware VM Consolldation scheme for Energy Conservation in Data CEnter to solve CVC. Instead of taking the unrealistic hypothesis that migration cost is negligible, a common assumption in most literatures, we precisely analyze VM migration cost according to real-trace experiments in a 6-server testbed via VMware. Massive simulations validate the efficiency of NICE. In all, to the best of our knowledge, we are the first work to combine VM consolidation with network optimization and migration cost.