Evaluation of fault tolerance latency from real-time application's perspectives

Information on Fault Tolerance Latency (FTL), which is defined as the total time required by all sequential steps taken to recover from an error, is important to the design and evaluation of fault-tolerant computers used in safety-critical real-time control systems with deadline information. In this paper, we evaluate FTL in terms of several random and deterministic variables accounting for fault behaviors and/or the capability and performance of error-handling mechanisms, while considering various fault tolerance mechanisms based on the trade-off between temporal and spatial redundancy, and use the evaluated FTL to check if an error-handling policy can meet the Control System Deadline (CSD) for a given real-time application.