Section: New Results

Unified model for assessing checkpointing protocols at extreme-scale

In this work [38] , we defined a unified model for several well-known checkpoint/restart protocols. The proposed model is generic enough to encompass both extremes of the checkpoint/restart space, from coordinated approaches to a variety of uncoordinated checkpoint strategies (with message logging). We identified a set of crucial parameters, instantiated them and compared the expected efficiency of the fault tolerant protocols, for a given application/platform pair. We then proposed a detailed analysis of several scenarios, including some of the most powerful currently available HPC platforms, as well as anticipated Exascale designs. The results of this analytical comparison are corroborated by a comprehensive set of simulations. Altogether, they outlined comparative behaviors of checkpoint strategies at very large scale, thereby providing insight that is hardly accessible to direct experimentation.