On the modelling of optimal coordinated checkpoint period in supercomputers

Abstract

This work revises current assumptions adopted in the checkpointing modelling and evaluates their impact on the attained prediction of the optimal coordinated single-level checkpoint period.Anaccurate a priori assessment of the optimal checkpoint period for a given computing facility is necessary as it drives the incurred overhead due to frequent checkpointing and, as a result, implies a drop in the resource steady-state availability. The present study discusses the impact of the order of approximation used in the singlelevel coordinated checkpoint modelling and follows on extending previous results of the optimal checkpoint period to explore the effects of the checkpoint rate on the cluster performance under total execution time and energy consumption policies, and in terms of resource availability. A consequence of a prescribed checkpoint rate with current technology is a critical size of the cluster above which the attained availability is too poor to become a cost-effective platform. Thus, some guidelines for the cluster sizing are indicated.