Remove AutoMPI?

AutoMPI is a boolean setting in ParaView that, when enabled, launches a server process with mpiexec when the ParaView client runs, then the client connects to that server. It was created as a convenient way to enable parallelism in ParaView back when most VTK algorithms were not multithreaded. These days, many VTK/ParaView filters are multithreaded to run on multiple cores, and this is usually faster than running separate MPI processes for parallelization of serial algorithms.

Should we remove AutoMPI?

Thanks Cory.
I’m leaning towards yes, we should remove the client side MPI option. Users don’t understand the nuance, and are just enabling MPI with numerous servers blindly, assuming more MPI ranks, the better. This is not true, generally speaking. Again, lets simplify, and remove the client side MPI option.

I don’t use the AutoMPI. I’ll check around a bit to see if others use it but I would suspect that the answer is no, we don’t use it. Thus, if it’s not used it is probably a good idea to remove it.

+1. While there are cases we can conceive where it’s useful, I don’t think it’s worth the confusion anymore.

For reference, this was discussed a bit a few month ago, on the dedicated issue:

https://gitlab.kitware.com/paraview/paraview/-/issues/20712

The only “correct” usage for AutoMPI is an educationnal one, to teach people about distributed ParaView without having to enter terminal command.

Not worth the confusion imo.

Ah. I missed that - thanks @mwestphal .

The customer I mentioned is no longer interested in Auto MPI, and Alan has changed his mind about removing it.

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Yep. I have always wanted threaded, as opposed to MPI, for the client.

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