SLA-guided energy savings for enterprise servers

Current hardware and operating system power management mechanisms use heuristics of a general nature that are largely application software independent, thus treating the application as a black box. The resulting communication disconnect between OS power management policies and application-level quality of service goals can either cause breaches in service level agreements (SLA) when the policies are too aggressive, or reduce energy savings when they are too conservative. In this work, we engage enterprise software in the management of its own performance and power by introducing a middleware that we call SLA Governor. The SLA Governor receives periodic updates on application level performance and the applicable SLA. Based on the available leeway and recent history, the SLA Governor makes, and puts into effect, decisions to raise or lower CPU speeds. Compared to state of the art OS based power management, the SLA Governor provides 8.3% better energy savings for an online transaction processing workload (TPoX) using a latest generation machine employing Intel E5-5600 (“Westmere”) series processors.