Determination of Optimal Checkpoint Intervals for Quintuple Modular Redundancy Real-Time Systems; 5중 구조 실시간 시스템을 위한 최적 체크포인터 구간 선정

초록

The paper proposes a novel checkpoint management method for a real-time system with a quintuple modular redundancy (QMR) structure wherein multiple fault detections are performed between checkpoints. If the detected faults can be overcome within the context of the QMR structure, they are recovered by simply synchronizing the state values. Otherwise, the system rollbacks to the most recent checkpoint and re-executes the task to recover from the faults. The real-time system having the QMR structure and incorporating the proposed checkpoint scheme is modeled by a Markov chain. Based on the Markov chain model, a probability equation is derived to calculate the likelihood of completing the real-time task within the deadline. The optimal number of checkpoints and fault detections maximizing the probability value are also determined. Numerical experiments are conducted to illustrate the optimization procedure of the real-time system with a QMR structure using the proposed checkpoint management method.

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