View source for Admin Guide Module Systems

[[Category:HPC-Admin|Module Systems]]
[[Category:HPC.NRW-Best-Practices|Module Systems]]
[[Category:Environment_Modules]]

= Software =

* [https://lmod.readthedocs.io/en/latest/ LMOD]
** Actively developed
** Integrated by EasyBuild
** In-build module usage tracking
** Support for different module naming schemes
** Supported languages: Lua and TCL
** Installation via [https://openhpc.community/ OpenHPC] repository package
* Alternative: [http://modules.sourceforge.net/ Environment Modules]
** Stale development
** Since 2018 new maintainer
** Supported languages: TCL

= Naming Conventions =

We are employing a so-called [https://easybuilders.github.io/easybuild/files/hust14_paper.pdf 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 –&gt; now the OpenMPI module is visible 2. module load OpenMPI –&gt; now the GROMACS module is visible 3. module load GROMACS

= Module Usage Tracking =

* Tracking of module usage can directly be integrated into LMOD –&gt; see https://lmod.readthedocs.io/en/latest/300_tracking_module_usage.html
* Rquirements: MariaDB (MySQL) and rsyslog functionality
* '''NOTE:''' Clone the [https://github.com/TACC/Lmod git repository] and look into the folder <code>contrib/tracking_module_usage</code> 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'' –&gt; e.g. <code>module load 2020a</code>
* 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