This website is a virtual proof that I'm awesome https://mpi-debug.org/ In a previous post, Debug an MPI code with GDB and Xterm, I mentioned the awkwardness of using xterm. Fortunately, Arno Mayrhofer introduced tmpi, a clever idea that leverages tmux for MPI debugging. tmux is a terminal multiplexer. It does not require an X11 server, so no special setup is... Fri, 20 Feb 2026 00:00:00 -0600 https://mpi-debug.org/2026-02-20-tmux/ https://mpi-debug.org/2026-02-20-tmux/ If you cannot debug your code with a single process, you eventually have to deal with multiple MPI processes. A traditional approach is to launch each process in a separate xterm window. Doing so requires a working X11 setup. On macOS, this means installing XQuartz, since no native X11 server... Wed, 28 Jan 2026 00:00:00 -0600 https://mpi-debug.org/2026-01-28-xterm/ https://mpi-debug.org/2026-01-28-xterm/ It may feel counterintuitive to debug an MPI program using a single process, yet this is often the very first approach you should take. There are two scenarios that this can be used. 1. Run with one process In many cases, bugs in parallel codes are not caused by MPI... Tue, 27 Jan 2026 00:00:00 -0600 https://mpi-debug.org/2026-01-27-one-process/ https://mpi-debug.org/2026-01-27-one-process/ I will be attending the US-RSE’25 conference in Philadelphia, PA, from October 6–8, 2025. I look forward to connecting with fellow research software engineers as well as current and past BSSw fellows. As science and engineering increasingly rely on computer simulation and modeling, research software—and the people who develop it—play... Fri, 03 Oct 2025 00:00:00 -0500 https://mpi-debug.org/2025-10-03-usrse25/ https://mpi-debug.org/2025-10-03-usrse25/ What, debug with printf? Yes, though it is so basic, it works if you only want to check some variables or want to see if a specific execution path is taken. It doesn’t need any tool support, is independent of compiler flags, can be local or remote, and works with... Thu, 17 Jul 2025 00:00:00 -0500 https://mpi-debug.org/2025-07-17-debug-with-printf/ https://mpi-debug.org/2025-07-17-debug-with-printf/ Human, as we are, use tools, powerful tools! Which tools do you use for MPI debugging and at what scale? Please take 5 seconds to complete this anonymous Google Forms survey (no email collecting) here so that I can highlight the most popular tools in future posts. Note: Previously, the... Wed, 25 Jun 2025 00:00:00 -0500 https://mpi-debug.org/2025-06-25-tool-survey/ https://mpi-debug.org/2025-06-25-tool-survey/ Building a Community Hub for MPI Program Debugging - If you’ve landed here, you’re probably already familiar with key MPI-related websites like mpich.org, open-mpi.org, and mpi-forum.org. As a PETSc developer, I write MPI code regularly—and debugging MPI programs is part of my daily routine. One day, I discovered that nobody had registered the domain mpi-debug.org. So, I bought it.... Wed, 25 Jun 2025 00:00:00 -0500 https://mpi-debug.org/2025-06-25-introduction/ https://mpi-debug.org/2025-06-25-introduction/