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<p class="MsoNormal">My application, which spawns multiple subprocesses via MPI_Comm_spawn, eventually fails on one Slurm cluster as I scale up the number of processes, with the error:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b>[mpiexec@n002.cluster.pssclabs.com] HYDU_create_process (../../../../mpich-4.0.1/src/pm/hydra/utils/launch/launch.c:21): pipe error (<span style="color:red">Too many open files</span>)<o:p></o:p></b></p>
<p class="MsoNormal"><b>[mpiexec@n002.cluster.pssclabs.com] HYDT_bscd_common_launch_procs (../../../../mpich-4.0.1/src/pm/hydra/tools/bootstrap/external/external_common_launch.c:296): create process returned error<o:p></o:p></b></p>
<p class="MsoNormal"><b>free(): invalid pointer<o:p></o:p></b></p>
<p class="MsoNormal"><b>/var/spool/slurm/job235999/slurm_script: line 296: 3778907 Aborted (core dumped)<o:p></o:p></b></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It works fine on a different (Torque) cluster for very large job sizes.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">“ulimit -n” (number of open files) on both machines returns 1024.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m hoping that there is some other system setting on the Slurm cluster that would allow larger jobs. I can provide the “-verbose” output file if that would help.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Kurt<o:p></o:p></p>
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