CASS: Criticality-Aware Standby-Sparing for real-time systems

The standby-sparing (SS) is a promising technique which deploys the dual-processor platform, i.e., one primary processor and one spare processor, to achieve fault tolerance for real-time systems. In the existing SS framework, all applications have their backup copies on the spare processor, but, in practice, not all applications on a system are equally important to the system. Some low critical tasks may be traded off for other system objectives. Motivated by this, in this paper, we integrate the concept of criticality into the SS framework. Such integration enables the SS framework to further reduce energy consumption. We propose an offline approach to determine an energy-efficient frequency for the primary processor. Additionally, as the cluster systems are emerging as the mainstream computing platform, we consider the SS technique on the cluster/island systems and propose an algorithm to determine the energy-efficient algorithm for such systems. We evaluate the proposed approach on synthetic tasks and real-platforms. The experimental results demonstrate the effectiveness of our proposed framework in terms of energy efficiency.