The OpenHPC community is pleased to announce the release of version 4.2 of the OpenHPC software stack.
This release adds a second option at several layers of the stack that previously had only one. Provisioner, resource manager, module system and the source of scientific software are now each an install-time
choice, and the install guide covers the combinations.
Provisioners
OpenHPC 4.2 ships install recipes for Warewulf 4, OpenCHAMI, Confluent and xCAT. xCAT is new in this release and is available in both stateless and stateful variants; the stateful variant installs the operating system to local disk on the compute nodes.
Resource managers
Flux is packaged and documented alongside Slurm. The release includes flux-core, flux-sched, flux-security and flux-pmix, and the install guide carries a Flux recipe.
Environment modules
Environment Modules 5.7 is packaged as an alternative to Lmod and is selected at install time through the modules_package recipe setting. OpenHPC’s hierarchical module tree works under either implementation, and both are covered by the test suite. This is the first OpenHPC release with a module system other than Lmod.
Scientific software
The install guide has an optional EESSI section that configures CernVM-FS and gives cluster nodes access to the EESSI software stack (enable_eessi, requires Lmod). Spack and EasyBuild remain packaged for sites that build their own.
Recipe Explorer
The Recipe Explorer at https://openhpc.github.io/ohpc/ renders the install guides in the browser. Selecting a base OS, architecture, provisioner and resource manager, and toggling the optional features to be enabled,
produces the guide for that configuration, along with the matching recipe.sh and input.local. Each chapter has a copyable deep link. It renders the same templates that produce the PDF.
Source verification
Each component carries an ohpc.checksums manifest with SHA-512 checksums of its upstream sources. An RPM macro verifies them at the start of %prep and aborts the build on a mismatch. This runs for every build without action by the packager.
Architectures
The build recipes now carry the patches needed to build OpenHPC on ppc64le, including compiler setup, POWER9 tuning for OpenBLAS, VSX SIMD for FFTW, and architecture support in Boost, LIKWID, GOTCHA, NumPy, UCX and PDToolkit. No ppc64le binary repositories are published.
OpenHPC publishes binary repositories for x86_64 and aarch64 on AlmaLinux 10, Rocky 10 and openEuler 24.03.
Component updates
GCC 16 is the new default compiler family. Other updates include Slurm 26.05, Open MPI 5.0.11, MPICH 5.0.2, UCX 1.22, HDF5 2.2.0, PETSc 3.26, Trilinos 17.2.1, Boost 1.92, Lmod 9.4.5, Spack 1.2.2, EasyBuild 5.4.1, Charliecloud 0.45.2, Score-P 10.1, CMake 4.4.4 and R 4.6.1. The full list of additions and version changes is in the release notes on GitHub.
RoCE is available as a fabric option (enable_roce) next to InfiniBand and Omni-Path.
HPSF projects in OpenHPC
Many of the components in this release come from projects in the High Performance Software Foundation (HPSF): Charliecloud, ClusterShell, Flux, Environment Modules, OpenCHAMI, Spack, Trilinos, EasyBuild, Open MPI and MPICH, alongside projects such as Apptainer. Some have joined HPSF and others are in the process of joining.
OpenHPC integrates them: they are built against the same compiler and MPI families, installed into one hierarchical module tree, tested together on real clusters, and documented in a single install guide. Testing them in combination across several distributions, architectures, compilers and MPI stacks also surfaces issues that individual projects do not see on their own. The OpenHPC community intends to continue this work with HPSF and its member projects.
Validation
OpenHPC 4.2 was validated with 172,794 tests over 306 hours of integration testing, covering the supported combinations of distribution, architecture, provisioner, resource manager and module system. aarch64 is fully tested again in this release; 4.1 was not, due to limited test resources at the time.
Getting started
Install guides, release RPMs and the component manifest are available from the OpenHPC 4.x wiki. The release notes are attached to the v4.2.GA tag on GitHub. The Recipe Explorer at https://openhpc.github.io/ohpc/ generates the recipe for a given configuration.
If you deploy OpenHPC, please consider registering your system with the project. It helps the community see which configurations are in use.