Virtual machine migration in cloud infrastructures: Problem formalization and policies proposal

Cloud computing has dramatically simplified the deployment of new software and, indeed, the number of applications that are hosted by cloud providers every day is increasing. The data center owner should provide computing capacity to a set of customers, each of them powering up and down virtual machines dynamically, to handle variations in the incoming requests. Cloud providers, however, should also optimize for quantities like energy consumption and managements costs, therefore trying to host all the customers virtual machines with the fewest amount of physical hardware machines possible. This leads to virtual machine co-location and potential performance inefficiency. To limit the inefficiency, virtual machines are migrated from one physical machine to another when overload conditions are detected. This paper analyzes the problem of virtual machine migration and presents some heuristic solutions to decide when to migrate a virtual machine from a physical machine to a different one. Experimental results show the differences between the proposed heuristics, providing a basis for a fair comparison among the techniques.