Enabling Continuous Testing of HPC Systems Using ReFrame.

Regression testing of HPC systems is of crucial importance when it comes to ensure the quality of service offered to the end users. At the same time, it poses a great challenge to the systems and application engineers to continuously maintain regression tests that cover as many aspects as possible of the user experience. In this paper, we briefly present ReFrame, a framework for writing regression tests for HPC systems and how this is used by CSCS, NERSC and OSC to continuously test their systems. ReFrame is designed to abstract away the complexity of the interactions with the system and to separate the logic of a regression test from the low-level details, which pertain to the system configuration and setup. Regression tests in ReFrame are simple Python classes that specify the basic parameters of the test plus any additional logic. The framework will load the test and send it down a well-defined pipeline which will take care of its execution. ReFrame can be easily set up on any cluster and its straightforward invocation allows it to be easily integrated with common continuous integration/deployment (CI/CD) tools, in order to perform continuous testing of an HPC system. Finally, its ability to feed the collected performance data to well known log channels, such as Syslog, Graylog or, simply, parsable log files, make it also a powerful tool for continuously monitoring the health of the system from user’s perspective.