How well do we really understand the temporal I/O behavior of HPC applications — and why does it matter?

Exa-DoST is proud to share its new publication at IPDPS 2025: A Deep Look Into the Temporal I/O Behavior of HPC Applications.

In collaboration between Inria (France), TU Darmstadt (Germany), and LNCC (Brazil), Francieli Boito, Luan Teylo, Mihail Popov, Theo Jolivel, François Tessier, Jakob Luettgau, Julien Monniot, Ahmad Tarraf, André Carneiro, and Carla Osthoff present a large-scale study of temporal I/O behavior in high-performance computing (HPC), based on more than 440,000 traces collected over 11 years from four large HPC systems.

Understanding temporal I/O behavior is critical to improving the performance of HPC applications, particularly as the gap between compute and I/O speeds continues to widen. Many existing techniques—such as burst buffer allocation, I/O scheduling, and batch job coordination—depend on assumptions about this behavior. This work examines fundamental questions about the temporality, periodicity, and concurrency of I/O behavior in real-world workloads. By analyzing traces from both system and application perspectives, we provide a detailed characterization of how HPC applications interact with the I/O subsystem over time.
Key contributions include:

• A classification of recurring temporal I/O patterns across diverse workloads.
• Insights into I/O concurrency and shared resource usage.
• Public release of the used large datasets to support further research.

Our findings offer a solid empirical foundation for future developments in behavior-aware monitoring, I/O scheduling, and performance modeling.

Read the full version on HAL.