A cost-effective forward recovery checkpointing scheme in multiprocessor systems

Abstract

This paper proposes a novel and cost-effective forward recovery checkpointing scheme fur multiprocessor systems with duplex modular redundancy. In our scheme, one processing module is selected to retry the questionable checkpoint, and the other processing module executes toward the next checkpoint ii a mismatched comparison between the two processing modules occurs at any checkpoint. Those schemes using a spare module to retry need much time to initiate the module, and the extra cost is high. Although the traditional rollback scheme retries the questionable checkpoint without any spare module, it has longer average completion time than our scheme for a job under any fault distribution. In our scheme, besides transient faults, permanent faults can be located as well. Experimental results based on our mathematical models demonstrate that, under burst errors, the average completion time of our scheme is reduced by 50% compared with that of the traditional rollback and is comparable with that of the scheme using a spare module to retry. In addition, our scheme has the least total execution time (the most cost-effectiveness) among the three schemes under any fault distribution.