Inter-and-Intra Data Center VM-Placement for Energy-Efficient Large-Scale Cloud Systems

Data centers play the crucial role in the delivery of Cloud services by enabling on-demand access to the shared resources such as software, platform, and infrastructure. Virtual Machine (VM) allocation is one of the challenging tasks in the data center management since user requirements, typically expressed as SLAs, have to be met with the minimum operational expenditure. Despite their huge processing and storage facilities, data centers are among the major contributors of the Green-House Gas (GHG) emissions of the IT services. In this paper, we propose a holistic approach for a large-scale Cloud system where the Cloud services are provisioned by several data centers interconnected over the backbone network. We propose a Mixed Integer Linear Programming (MILP) formulation that aims at virtualizing the backbone topology and placing the VMs in data centers with the objective of minimum power consumption. We compare our proposed solution with a benchmark MILP model which selects the closest data centers that can accommodate the user requests taking into account the CPU, memory, and bandwidth capacities of the residing physical hosts. Collected experimental results show the benefit of the proposed management scheme in terms of power consumption, resource utilization, and fairness for medium size data centers.