Open MPI developers,
The v5.0 RM managers would like to solicit opinions to come to consensus
around our three independent MCA frameworks in Open MPI v5.0.x.
around our three independent MCA frameworks in Open MPI v5.0.x.
As you know, Open MPI v5.0.x has abstracted the runtime away to use
the Open PMIx Reference Runtime Environment (PRRTE) implementation.
the Open PMIx Reference Runtime Environment (PRRTE) implementation.
In doing so, many of MCA paremeters are now different as they're
read in by PRRTE.
The problem is that this affects some vary common components, for
example `--oversubscribe`, which is now "--map-by :OVERSUBSCRIBE".
prterun prints a nice warning message, but that is not true for many
mca parameters that may never get read in at ALL in Open MPI v5.0.x
where they were accepted and used in earlier versions.
This means that users will need to use both ompi_info and prte_info
to understand how to translate their MCA parameters, and furthermore
there is no safety net if an old parameter is not read in with the
new Open MPI v5.0.x releases.
If someone is interested in writing an aliasing system that might
help users adopt Open MPI, that would be FANTASTIC. However, it
doesn't help educate users for the long term.
For this reason, the Open MPI v5.0 Release Managers are recommending
that we document this loudly on the website for Open MPI v5.0.0.
What are other's thoughts? Lets discuss on the devel mailing list:
<devel at lists dot open dash mpi dot org>
Let's try to come to consensus by Nov 15th.
Thanks,
The Open MPI v5.0 Release Managers,
Tommy, Austen, Geoff
