Title
Adaptive control in roll-forward recovery for extreme scale multigrid
Abstract
AbstractWith the increasing number of compute components, failures in future exa-scale computer systems are expected to become more frequent. This motivates the study of novel resilience techniques. Here, we extend a recently proposed algorithm-based recovery method for multigrid iterations by introducing an adaptive control. After a fault, the healthy part of the system continues the iterative solution process, while the solution in the faulty domain is reconstructed by an asynchronous online recovery. The computations in both the faulty and the healthy subdomains must be coordinated in a sensitive way, in particular, both under- and over-solving must be avoided. Both of these waste computational resources and will therefore increase the overall time-to-solution. To control the local recovery and guarantee an optimal recoupling, we introduce a stopping criterion based on a mathematical error estimator. It involves hierarchically weighted sums of residuals within the context of uniformly refined meshes and is well-suited in the context of parallel high-performance computing. The recoupling process is steered by local contributions of the error estimator before the fault. Failure scenarios when solving up to 6.9 × 1011 unknowns on more than 245,766 parallel processes will be reported on a state-of-the-art peta-scale supercomputer demonstrating the robustness of the method.
Year
DOI
Venue
2018
10.1177/1094342018817088
Periodicals
Keywords
Field
DocType
Algorithm-based fault tolerance, high-performance computing, multigrid methods, error estimator, adaptive recovery
Asynchronous communication,Mathematical optimization,Polygon mesh,Supercomputer,Computer science,Robustness (computer science),Theoretical computer science,Adaptive control,Multigrid method,Computation,Estimator
Journal
Volume
Issue
ISSN
33
5
1094-3420
Citations 
PageRank 
References 
0
0.34
38
Authors
3
Name
Order
Citations
PageRank
Markus Huber1213.12
Ulrich Rüde2383.97
Barbara I. Wohlmuth332050.97