Hierarchical Power Control for Large-Scale Data Centers

In today’s data centers, precisely controlling power consumption is an essential way to 1) reduce operating costs, and 2) avoid system failures caused by power capacity overload or overheating due to increasingly high server density. While various power control strategies have been recently proposed, existing solutions are not scalable to control the power consumption of an entire large-scale data center, because these solutions are designed only for a single server or a rack enclosure. In today’s data centers, however, power control needs to be enforced at three levels: rack enclosure, power distribution unit, and an entire data center, due to the physical and contractual power limits at each level. This paper proposes a highly scalable hierarchical control architecture for large-scale data centers, which is designed based on well-established control theory for analytical assurance of control accuracy and system stability. Empirical results on a physical testbed show that our control solution can provide precise power control, as well as power differentiations for optimized system performance and desired server priorities. Our solution also outperforms a state-of-the-art centralized control solution by having better benchmark performance. In addition, extensive simulation results based on a real trace file demonstrate the efficacy of our control solution in large-scale data centers composed of thousands of servers.