A Backward/Forward Recovery Approach for the Preconditioned Conjugate Gradient Algorithm
Résumé
Several recent papers have introduced a periodic verification mechanism to
detect silent errors in iterative solvers. Chen [PPoPP'13, pp. 167--176] has
shown how to combine such a verification mechanism (a stability test checking
the orthogonality of two vectors and recomputing the residual)
with checkpointing: the idea is to verify every $d$ iterations, and to
checkpoint every $c \times d$ iterations. When a silent error is detected by
the verification mechanism, one can rollback to and re-execute from the last
checkpoint.
In this paper, we also propose to combine checkpointing and verification, but
we use algorithm-based fault tolerance (ABFT) rather than stability tests.
ABFT can be used for error detection,
but also for error detection and correction, allowing a forward recovery (and
no rollback nor re-execution) when a single error is detected. We introduce an
abstract performance model to compute the performance of all schemes, and we
instantiate it using the preconditioned conjugate gradient algorithm.
Finally, we validate our new approach through a set of simulations.
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...