Thanks Jeff. Given that this is an intended behavior, I have a couple of follow up questions:
1. What is the purpose of the directory “1” that gets created currently? (in <log directory>/app.log/1/rank.<i>/stdout ) Is this hard-coded to “1” or could be something else? 2. Mpirun also has an option “—merge-stderr-to-stdout”, that allows us to merge the stderr into stdout, so we are left with only 1 file (‘stdout’). Are there any future change that we need to worry about in using this option to merge the 2 streams? Regards, Vipul From: Jeff Squyres (jsquyres) [mailto:jsquy...@cisco.com] Sent: Tuesday, October 29, 2019 9:07 PM To: Open MPI User's List <users@lists.open-mpi.org> Cc: Kulshrestha, Vipul <vipul_kulshres...@mentor.com> Subject: Re: [OMPI users] mpirun --output-filename behavior On Oct 29, 2019, at 7:30 PM, Kulshrestha, Vipul via users <users@lists.open-mpi.org<mailto:users@lists.open-mpi.org>> wrote: Hi, We recently shifted from openMPI 2.0.1 to 4.0.1 and are seeing an important behavior change with respect to above option. We invoke mpirun as % mpirun –output-filename <log directory>/app.log –np <n> <application command line> With 2.0.1, the above produced <log directory>/app.log.<i> file for stdout of the application, where <i> is the rank of the process. However, with 4.0.1, the above produces <log directory>/app.log/1/rank.<i>/stdout Is this intentional change? The documentation does not seem to indicate any expected changes in the behavior. How do I get 4.0.1 to get log files as seen in 2.0.1? This was reported recently here: https://github.com/open-mpi/ompi/issues/7095 It looks like we changed this behavior quite some time ago, and neglected to update the documentation. :-\ Further, earlier, mpirun had no output on stdout, except to indicate, when all the child process had completed. However, now the mpirun also spews out all the application stdout messages (from each rank process) on its stdout. How do I stop that? Oh, did the prior behavior *only* output to the file and not to stdout/stderr? Huh. I guess a workaround for that would be: mpirun ... > /dev/null -- Jeff Squyres jsquy...@cisco.com<mailto:jsquy...@cisco.com>
