A Bayesian Reliability Analysis of Neutron-Induced Errors in High Performance Computing Hardware

Abstract

A soft error is an undesired change in an electronic device's state, for example, a bit flip in computer memory, that does not permanently affect its functionality. In microprocessor systems, neutron-induced soft errors can cause crashes and silent data corruption (SDC). SDC occurs when a soft error produces a computational result that is incorrect, without the system issuing a warning or error message. Hence, neutron-induced soft errors are a major concern for high performance computing platforms that perform scientific computation. Through accelerated neutron beam testing of hardware in its field configuration, the frequencies of failures (crashes) and of SDCs in hardware from the Roadrunner platform, the first Petaflop supercomputer, are estimated. The impact of key factors on field performance is investigated and estimates of field reliability are provided. Finally, a novel statistical approach for the analysis of interval-censored survival data with mixed effects and uncertainty in the interval endpoints, key features of the experimental data, is presented. Supplementary materials for this article are available online.

KEY WORDS:

• Accelerated testing
• Cox proportional hazards
• Gaussian process
• Mixed effects
• Neutron beam
• Silent data corruption
• Stochastic search variable selection

Acknowledgments

Many people contributed to the success of the Triblade beam-testing experiments. The authors thank Joe Abeyta, Chuck Alexander, Ben Bergen, Derek Bingham, Sean Blanchard, Ann Borrett, Henry Brandt, James Campa, Randy Cardon, Nathan DeBardeleben, Tom Fairbanks, Parks Fields, Alan Gibson, Gary Grider, Josip Loncaric, Pablo Lujan, Alex Malin, Andrea Manuzzato, Fred Marshall, David Modl, Andrew Montoya, John Morrison, Bill Rust, Andrew Shewmaker, Manuel Vigil, Bob Villa, Cornell Wright, and the reviewers of the IEEE TDMR article documenting some more of these results, and apologize for any inadvertent omissions from this list. This work was funded by Los Alamos National Security, LLC (LANS), operator of the Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396 with the U.S. Department of Energy. This article is published under LA-UR 11-04750.