Replicated Imprecise Computations for Fault-Tolerant Real-Time Systems
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Many real-time systems must be fault-tolerant and must handle failures in a timely manner. An approach incorporating the redundancy-masking technique and the imprecise computation model is presented in this paper. The redundancy-masking technique is preferred for time-critical applications than the rollback-and-retry techniques because of the fast error detection and the potential for forward error recovery. The imprecise computation model provides flexible functionality by trading off the quality of the result produced by a task with the amount of processing time required to produce it. It therefore permits the performance of a real-time system to degrade gracefully. Several algorithms for scheduling replicated periodic tasks on a real-time multiprocessor system have been studied and evaluated by stochastic analysis and Monte Carlo simulations. The results show that the algorithms are resilient under hardware failures.
KeywordsSchedule Algorithm Task Allocation Processor Utilization Task System Early Deadline First
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