(let's keep users@lists.open-mpi.org in the CC list so that others can reply,
too)
I don't know exactly how conda installs / re-installs mpi4py -- e.g., I don't
know which MPI implementation it compiles and links against.
You can check to see which MPI implementation mpiexec uses -- for Open MPI, you
should be able to run "mpiexec --version" and it should have "Open MPI"
somewhere in the output. I suspect MPICH's mpiexec will show something else
(at a bare minimum, it won't have "Open MPI" in the output).
After that, you might look to see if the conda package documentation describes
which MPI implementation it uses, and/or if it has instructions about choosing
which one it uses. I'm afraid I don't have much more detail here; we don't
have much control on how the downstream packages bundle up Open MPI and/or use
it.
From: caitlin lamirez
Sent: Wednesday, October 25, 2023 1:17 PM
To: Jeff Squyres (jsquyres)
Subject: Re: [OMPI users] MPI4Py Only Using Rank 0
Hi Jeff,
After getting that error, I did reinstall MPI4py using conda remove mpi4py and
conda install mpi4py. However, I am still getting the same error. If I did
happen to accidentally switch to a different MPI implementation, what should I
do to fix this?
Thank you,
Caitlin
On Wednesday, October 25, 2023 at 12:05:15 PM CDT, Jeff Squyres (jsquyres)
wrote:
This usually means that you have accidentally switched to using a different
MPI implementation under the covers somehow. E.g., did you somehow
accidentally start using mpiexec from MPICH instead of Open MPI? Or did MPI4Py
somehow get upgraded or otherwise re-build itself for MPICH, but you're still
using the mpiexec from Open MPI? Stuff like that.
From: users on behalf of caitlin lamirez via
users
Sent: Wednesday, October 25, 2023 11:57 AM
To: users@lists.open-mpi.org
Cc: caitlin lamirez
Subject: [OMPI users] MPI4Py Only Using Rank 0
Hello,
I am having a problem with MPI4Py (version: mpiexec (OpenRTE) 4.1.5). I have
been using it for months without a problem, however, out of no where, I am
getting a bug where my program is only using Rank 0.
For example, when I run the command:
mpiexec -n 5 python -m mpi4py.bench helloworld
I get the following output:
Hello, World! I am process 0 of 1 on Caitlins-MacBook-Air.local.
Hello, World! I am process 0 of 1 on Caitlins-MacBook-Air.local.
Hello, World! I am process 0 of 1 on Caitlins-MacBook-Air.local.
Hello, World! I am process 0 of 1 on Caitlins-MacBook-Air.local.
Hello, World! I am process 0 of 1 on Caitlins-MacBook-Air.local.
I have not changed anything with my system. I was wondering if I can get some
help on this issue?
Thank you,
Caitlin Lamirez
