Energy efficient scheduling for web search on heterogeneous microservers

Heterogeneous multi-core processors, such as the ARM big-LITTLE architecture, are becoming increasingly popular due to power and thermal constraints. In this paper, we address the use of low-power heterogeneous multi-cores as microservers utilizing web search as a motivational application. In particular, we propose a new family of scheduling policies for heterogeneous microservers to optimize for performance metrics such as mean response time and service level agreements, while guaranteeing thermally-safe operation. Thorough experimental evaluations on a big-LITTLE platform demonstrate that naive performance-oriented scheduling policies quickly result in thermal instability, while the proposed policies not only reduce peak temperature but also achieve 4.8× reduction in processing time and 5.6× increase in energy efficiency compared to baseline scheduling policies.