A streams manager monitors performance of a streaming application on a physical machine, and determines operators that are underperforming and operators that are overperforming. When the performance needs to be improved, the streams manager automatically modifies the flow graph to deploy one or more operators of the streaming application that are overperforming to a virtual machine in a cloud. Moving the overperforming operators off of the physical machine to a VM leaves additional resources for the underperforming operators that are left on the physical machine to improve performance of the streaming application.