Brussels / 3 & 4 February 2018


Behind the scenes of a FOSS-powered HPC cluster at UCLouvain

Ansible or Salt? Ansible AND Salt!

With the advent of the DevOps and Infrastructure as Code movements, tools have emerged that allow building a complete HPC solution from scratch based only on open source software. At UCLouvain, one of our clusters, and the services on which it depends, is built on a full FOSS stack. From the operating system, to the deployment tools, monitoring, scheduling, and user software installation, everything is built from open source software that inter-operate gracefully. For instance, for deployment/provisioning, we use a combination of Ansible and Salt which we find work perfectly together even if they are often considered to be mutually exclusive. This talk will share our experience with making FOSS software co-operate smoothly and will offer our point of view on choosing the right tool for the right job. It will also present some of the contributions we have made to the open source community.

Our software stack for the cluster is based on Slurm, OpenLDAP, Easybuild, Zabbix, with many side-services running on virtual machines in OpenStack. Management is performed with a trilogy of tools: Cobbler, Ansible and Salt, for production, and Openstack and Vagrant for development and staging.

Our contributions to the open source community include somme tools for Slurm, a web wizard for building submission scripts, and a tool that orchestrates the interplay between the LDAP system and the job submission program (Slurm).


Damien Fran├žois