Energy-Constrained Standby-Sparing for Weakly Hard Real-Time Systems

For real-time embedded systems, QoS (Quality of Service), fault tolerance, and energy budget constraint are among the primary design concerns. In this research, we investigate the problem of energy constrained standby-sparing for weakly hard real-time systems. The standby-sparing systems adopt a primary processor and a spare processor to provide fault tolerance for both permanent and transient faults. With the purpose of ensuring the feasibility of such kind of systems, we firstly present two novel scheduling schemes for the standby-sparing systems with tighter energy budget constraint than the traditional ones. Then based on them a hybrid approach is proposed to achieve better performance. The evaluation results demonstrated that the proposed techniques significantly outperformed the existing state of the art approaches in terms of feasibility and system performance while ensuring QoS and fault tolerance under given energy budget constraint.