Drishti VOL: The Performance Profiling and Tracing HDF5 VOL Connector

Drishti (https://github.com/hpc-io/drishti) is an interactive I/O analysis framework that seeks to close the gap between trace collection, analysis, and tuning by detecting common root causes of I/O performance inefficiencies and providing actionable user recommendations. In this talk, we demonstrate how Drishti can combine different sources of metrics and traces to provide a deeper understanding of I/O problems. Considering HDF5-based applications, we proposed the Drishti passthrough VOL connector to trace relevant high-level HDF5 calls that can be easily combined with other sources of I/O metrics, such as Darshan traces, to provide a cross-layer analysis and enhance the insights. We discuss our motivation and design choices and demonstrate how this HDF5 connector can aid in pinpointing the root causes of I/O performance bottlenecks.