Power-efficient Server Utilization in Compute Clouds

High performance servers of data centers for cloud computing consume immense amounts of energy even though they are usually underutilized because they provide huge computing capabilities. In times when not all of those computing capabilities are needed the task to be solved is how to distribute the load in a power-efficient manner. The research question is: How should a requested compute load be mapped to the available physical servers so that it is executed with the minimum power consumption? The requested load is measured in operations per seconds and changes over time. In this work, we assume that it is divisible which means that portions of the requested load can be freely assigned to different servers. This assumption is plausible because the load of a typical compute cloud consists of many virtual machines (VM). Our investigations are based on the SPECpower benchmark, retrieved Jan 9, 2013. SPECpower relies on Server Side Java (SSJ) for measuring power consumption of servers at different load levels running Java applications [7].