mpi4py-installer

A simple installer to manage mpi4py install variants on HPC systems (using pip). mpi4py_installer uses pip install --no-cache-dir --no-binary=:all: to install mpi4py, together with pre-defined compiler definitions. This ensures that mpi4py is built and linked against the system's MPI implementation.

Features

mpi4py_installer is detects the system it's running on automatically -- based on the site's automatic detection rules. If your site supports full automatic configuration, then all you need to do is run:

curl -fsSL https://github.com/JBlaschke/mpi4py-installer/releases/latest/download/install.sh | sh

from within your python or conda environment. For more control, it is recommended that you pip install mpi4py-installer and run mpi4py_installer as a python package.

Automatic Everything

mpi4py_installer detects the site (HPC center) and system that it's running on. It also comes configured with default build variants for each system. If you are happy with the sysadmin's defaults, all you need to do is run:

python -m mpi4py_installer

That's it! But there are many ways you can take control -- as described in the following sections.

Automatically Detect System

mpi4py_installer uses <site name>.dertermine_system() to detect which system it is running on. For cross-site builds, you can overwrite this using: --system=<system name>. Eg:

python -m mpi4py_installer --site=nersc --system=perlmutter

Display Available Variants for a given Site and System:

mpi4py_installer uses <site name>.available_variants(system) to display the available build vaiants. Setting --show-variants from the CLI activates this mode. This modes does not install mpi4py, instead prints a list of the avariants (default variant is designated using *). E.g:

python -m mpi4py_installer --site=nersc --show-variants

will display the variants available on this system at NERSC.

Set Build Variants

The --variant=<variant name> input flag sets the build variants. Build variants can be any string, but the recommended format is: system_partition:compiler_name -- e.g. gpu:nvidia. Eg:

python -m mpi4py_installer --site=nersc --variant=gpu:nvidia

Logging

By default minimal logging is displayed (after all, this is not drain surgery). WHen someing goes wrong though, you can enable debug mode by lowering the log level using the --log-level=10 flag. The logger is programatically accessible as: mpi4py_installer.logger.

For Sysadmins

Do you want to add your site or system to the machines supports out-of-the-box? Easy, submit a PR to add site_name.py to sites/. site_name.py needs to define the following functions:

• check_site() -> bool: a function that is true only when run on your center's systems -- mpi4py_installer will call this function for every registered site. If more than on site's check_site() returns True, automatic site resolution fails. Often this is done by checking for the presence of a particular environment variable, or the machine's hostname.
• determine_system() -> str: a function that can dermine the name (returned as a string) of the system that it's currently running on. Often this is done by checking for the presence of a particular environment variable, or the machine's hostname.
• available_variants(system: str) -> list[str] returns a list of all avialable variants on system.
• auto_variant(system: str) -> str: a function that returns the name of the default variant on system.
• config(system: str, variant: str) -> dict[str, str] returns a dictionary containing the following keys:
  • 'sys_prefix': the path prefix of a system (module) version of python. Any python executable that starts with this path will be assumed to have a read-only site-pacakges.
  • 'CC', 'MPICC', 'CFLAGS' control the compiler and CLFAGS used by the compiler.
• init(system: str, variant: str) -> str returns the bash commands that must preceede the MPICC=... pip install ... command. Eg. module load statements go here.
• sanity(system: str, variant: str, config: dict[str, str]) -> bool returns true if the mpi4py configuration matches what you expect.

Logging and Debugging

We recommend that you log the inputs to your site-configuration functions, eg:

def sanity(system: str, variant: str, config: dict[str, str]) -> bool:
    logger.debug(f"{system=}, {variant=}, {config=}")

This way you can most easily answer trouble-tickets by asking the user to set --log-level=10. Any user configurations that might influence the setup logic would be apparent here.