Variation-aware Server Placement and Task Assignment for Data Center Power Minimization

Size and number of data centers are fast growing all over the world and their increasing total power consumption is a worldwide concern. Moreover, increase in the amount of process variation in nanometer technologies and its effect on total power consumption of servers has made it inevitable to move toward variation-aware power reduction strategies. This paper formulates a variation-aware joint server placement and task assignment method using Integer Linear Programming (ILP) to minimize total power consumption of data centers. We first determine the optimum placement of servers in the data center racks based on total power consumption of each server and the data center recirculation model obtained by Computational Fluid Dynamics (CFD) simulations. Then, we dynamically consolidate the ON servers in chassis and racks such that the use of power-greedy servers is minimized. Experimental results reveal up to 14.85% and an average of 8.92% power saving at different server utilization rates with respect to conventional methods.