Evaluating System-Level Monitors and Knobs on Real Hardware

This chapter evaluates and defines a methodology for the oracle selection of the monitors and knobs to use to configure an HPC system running a scientific application while satisfying the application’s requirements and not violating any system constraints. This methodology relies on a heuristic correlation analysis between requirements, monitors, and knobs to determine the minimum subset of monitors to observe and knobs to explore to determine the optimal system configuration for the HPC application. The setup under examination is the Floreon+ application, along with IT4I’s cluster. At the end of this analysis, the eleven-dimensional was reduced to a three-dimensional space for monitors and a six-dimensional space to a three-dimensional space for knobs. This reduction shows the potential and highlights the need for a realistic methodology to help identify such a minimum set of monitors and knobs. Additionally, a characterization of the application is provided by showing that Floreon+ performance requirements are satisfied with a CPU frequency lower than the servers nominal CPU frequency.