vSensor: leveraging fixed-workload snippets of programs for performance variance detection

Abstract

Performance variance becomes increasingly challenging on current large-scale HPC systems. Even using a fixed number of computing nodes, the execution time of several runs can vary significantly. Many parallel programs executing on supercomputers suffer from such variance. Performance variance not only causes unpredictable performance requirement violations, but also makes it unintuitive to understand the program behavior. Despite prior efforts, efficient on-line detection of performance variance remains an open problem.