Re-Powering Service Provisioning Through Virtual Machine Migration in Federated Cloud Environments: An Algorithm Combining Energy Sustainability and Cost-Saving Strategies

Cloud federation offers new business models to enforce more flexible energy management strategies. Typically, an independent Cloud provider is exclusively bounded to the specific energy supplier powering its data center. The situation radically change if we consider a federation of cooperating Cloud providers. In such a context a proper migration of virtual machines among providers can lead to global energy sustainability and cost-saving strategies. 
In this paper, we discuss a decision algorithm, for Cloud federation brokerage, able to combine these two strategies. More specifically, we present a Multi-Criteria Decision Making (MCDM) algorithm able to discover the most convenient Cloud provider candidates to join a particular energy-aware federation. In the end, by modelling different possible real Cloud providers, we demonstrate how the algorithm can accommodate different Cloud federation scenarios characterized by particular energy-aware parameters.