1. A method comprising: executing a plurality of virtual machines on a plurality of nodes of a cluster computing system, wherein at least one application is executed within each of said plurality of virtual machines; generating data that is related to performance of said applications in said virtual machines; analyzing, by a management process, said data in view of parameters that encode desired performance levels of said applications; migrating, by said management process, a virtual machine on a first node to a second node of said plurality of nodes in response to said analyzing; and wherein said analyzing further comprises determining whether resources are available on said first node for allocation to said virtual machine before performing said migrating, and changing relative entitlement parameters associated with said virtual machine and at least one other virtual machine on said first node in response to said analyzing.