Mercury and freon

Abstract

Power densities have been increasing rapidly at all levels of server systems. To counter the high temperatures resulting from these den- sities, systems researchers have recently started work on softwa- re-based thermal management. Unfortunately, research in this new area has been hindered by the limitations imposed by simulators and real measurements. In this paper, we introduce Mercury, a soft- ware suite that avoids these limitations by accurately emulating temperatures based on simple layout, hardware, and component- utilization data. Most importantly, Mercury runs the entire software stack natively, enables repeatable experiments, and allows the study of thermal emergencies without harming hardware reliability. We validate Mercury using real measurements and a widely used com- mercial simulator. We use Mercury to develop Freon, a system that manages thermal emergencies in a server cluster without unneces- sary performance degradation. Mercury will soon become available from http://www.darklab.rutgers.edu.