Module Systems (Admin Guide)

Software

• LMOD
  • Actively developed
  • Integrated by EasyBuild
  • In-build module usage tracking
  • Support for different module naming schemes
  • Supported languages: Lua and TCL
  • Installation via OpenHPC repository package
• Alternative: Environment Modules
  • Stale development
  • Since 2018 new maintainer
  • Supported languages: TCL

Naming Conventions

We are employing a so-called hierarchical module naming scheme. This means that only those modules are shown to the user which can be loaded based on the current user environment.

Example: A user wants to load the module GROMACS which depends on the GCC compiler and open OpenMPI library. By default the user can only see the GCC module: 1. module load GCC –> now the OpenMPI module is visible 2. module load OpenMPI –> now the GROMACS module is visible 3. module load GROMACS

Module Usage Tracking

• Tracking of module usage can directly be integrated into LMOD –> see https://lmod.readthedocs.io/en/latest/300_tracking_module_usage.html
• Rquirements: MariaDB (MySQL) and rsyslog functionality
• NOTE: Clone the git repository and look into the folder contrib/tracking_module_usage to find the examples and scripts described in the guide above

Deprecated Modules

• Create a separate software stack every 6 to 12 months and create meta modules for the users to explicitly load a specific year –> e.g. module load 2020a
• This way, users get a feeling for how old their used software is
• You can easily deprecate older software stacks by just deleting the meta module but at the same time keep the software stack for archival purposes
• Module trees do not get cluttered