Feedback Driven QoS-Aware Power Budgeting for Virtualized Servers

Technological advances including multicore processors and small form factor blade servers are enabling continued improvements in computing densities for modern datacenters. Large scale facilities leverage these densities to deploy web applications and cloud based services, but must simultaneously address the ensuing power and cooling management issues that impact datacenter sustainability and costs. Virtualization has emerged as an enabling underlying technology for meeting datacenter management needs, accelerating its deployment onto enterprise servers. In this paper, we consider how a key power management capability, server power budgeting, can be provided through the virtualization management layer. Our approach utilizes feedback controllers that are designed to address two goals. The first goal is to honor platform power budgets. This is achieved using a feedback controller that monitors server power consumption and determines a platform-level CPU allocation that conforms to a power budget. The second goal is to enable QoS-aware management of virtual machines under imposed power constraints. To achieve this, additional feedback controllers are distributed across guest virtual machines (VMs). These controllers react to “shadow prices” provided by the system resource manager with resource bids based upon the QoS requirements of the VM. Finally, the resource manager combines the information from the power budget controller and guest QoS controllers to determine VM allocations. An evaluation of our system using the Hyper-V virtualization platform highlights the feasibility and benefits of feedback based control for QoS-aware power budgeting.