Characterizing output bottlenecks in a supercomputer


Journal Article

Supercomputer I/O loads are often dominated by writes. HPC (High Performance Computing) file systems are designed to absorb these bursty outputs at high bandwidth through massive parallelism. However, the delivered write bandwidth often falls well below the peak. This paper characterizes the data absorption behavior of a center-wide shared Lustre parallel file system on the Jaguar supercomputer. We use a statistical methodology to address the challenges of accurately measuring a shared machine under production load and to obtain the distribution of bandwidth across samples of compute nodes, storage targets, and time intervals. We observe and quantify limitations from competing traffic, contention on storage servers and I/O routers, concurrency limitations in the client compute node operating systems, and the impact of variance (stragglers) on coupled output such as striping. We then examine the implications of our results for application performance and the design of I/O middleware systems on shared supercomputers. © 2012 IEEE.

Full Text

Duke Authors

Cited Authors

  • Xie, B; Chase, J; Dillow, D; Drokin, O; Klasky, S; Oral, S; Podhorszki, N

Published Date

  • December 1, 2012

Published In

Electronic International Standard Serial Number (EISSN)

  • 2167-4337

International Standard Serial Number (ISSN)

  • 2167-4329

Digital Object Identifier (DOI)

  • 10.1109/SC.2012.28

Citation Source

  • Scopus