Implementation of Backward Recovery Mechanism in Preemptive Utility Accrual Real Time Scheduling Algorithm

This paper proposed a robust algorithm named as Backward Recovery Preemptive Utility Accrual Scheduling (BRPUAS). The proposed algorithm solved the abortion problem in the existing TUF/UA scheduling paradigm known as ARPUAS that only considers the abortion recovery as their fault recovery solution. BRPUAS enables the re-execution of the affected tasks rather than abortion to reduce the number of aborted tasks. It ensures the correctness of the executed tasks in the best effort basis in such a way that the infeasible tasks are aborted and produced zero utility, while the feasible tasks are re-executed to produce positive utility and consequently maximizing the total accrued utility to the system. Simulation results revealed that the BRPUAS achieved higher accrued utility compared to the ARPUAS for the entire load range, making it more reliable and efficient for adaptive real time application domain.