Energy-Aware Standby-Sparing Technique for Periodic Real-Time Applications

In this paper, we present an energy-aware standby-sparing technique for periodic real-time applications. A standby-sparing system consists of a primary processor where the application tasks are executed using Dynamic Voltage Scaling (DVS) to save energy, and a spare processor where the backup tasks are executed at maximum voltage/frequency, should there beaneed. In our framework, we employ Earliest-Deadline-First (EDF) and Earliest-Deadline-Late (EDL) scheduling policies on the primary and spare CPUs, respectively. The use of EDL on the spare CPU allows delaying the backup tasks on the spare CPU as much as possible, enabling energy savings. We develop static and dynamic algorithms based on these principles, and evaluate their performance experimentally. Our simulation results show significant energy savings compared to existing reliability-aware power management (RAPM) techniques for most execution scenarios.