An evaluation of the state of time synchronization on leadership class supercomputers. (9th October 2017)

• Record Type: Journal Article
• Authors: Jones, Terry; Ostrouchov, George; Koenig, Gregory A.; Mondragon, Oscar H.; Bridges, Patrick G.
• Is Part Of: Concurrency and computation. Volume 30:Number 4(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-10-09
• Subjects: clock synchronization -- large‐scale systems -- system software -- time service; Parallel processing (Electronic computers) -- Periodicals; Parallel computers -- Periodicals; 004.35
• DOI: 10.1002/cpe.4341
• Languages: English
• ISSNs: 1532-0626

Abstract

Summary: We present a detailed examination of time agreement characteristics for nodes within extreme‐scale parallel computers. Using a software tool we introduce in this paper, we quantify attributes of clock skew among nodes in three representative high‐performance computers sited at three national laboratories. Our measurements detail the statistical properties of time agreement among nodes and how time agreement drifts over typical application execution durations. We discuss the implications of our measurements, why the current state of the field is inadequate, and propose strategies to address observed shortcomings.