NAME

       mpi.conf - Slurm configuration file to allow the configuration of MPI plugins.

DESCRIPTION

       mpi.conf  is  an  ASCII  file  which  defines  parameters that control the behavior of MPI
       plugins. Currently the configuration file can only be used to configure the  PMIx  plugin,
       but  it  can  be  extended  to  support other MPI plugins as well. The file will always be
       located in the same directory as the slurm.conf. This file is optional.

       Parameter names are case insensitive. Any text following a "#" in the  configuration  file
       is  treated  as a comment through the end of that line.  Changes to the configuration file
       take effect upon restart of Slurm  daemons,  daemon  receipt  of  the  SIGHUP  signal,  or
       execution of the command "scontrol reconfigure" unless otherwise noted.

       Settings  from  this  configuration  file  can  be  viewed in the output of "scontrol show
       config". This configuration file can be included when using "configless" mode. Information
       from mpi.conf is read at startup or upon reconfigure by slurmctld and slurmd. Instances of
       slurmstepd for batch steps will  receive  information  about  the  plugin  requested  from
       slurmd.

PARAMETERS

       PMIxCliTmpDirBase=<path>
              Directory to have PMIx use for temporary files.  Defaults to not being set.

       PMIxCollFence={mixed|tree|ring}
              Define  the  type  of fence to use for collecting inter-node data.  Defaults to not
              being set. See also PMIxFenceBarrier.

       PMIxDebug={0|1}
              Enable debug logging for the PMIx plugin.  Defaults to 0.

       PMIxDirectConn={true|false}
              Disable direct launching of tasks. Default is "true".

       PMIxDirectConnEarly={true|false}
              Allow early connections to a parent node.  Defaults to "false".

       PMIxDirectConnUCX={true|false}
              Allow PMIx to use UCX for communication.  Defaults to "false".

       PMIxDirectSameArch={true|false}
              Enable additional communication optimizations when PMIxDirectConn is set  to  true,
              assuming all the job's nodes have the same architecture.  Defaults to "false".

       PMIxEnv=<environment variables>
              Semicolon  separated list of environment variables to be set in job environments to
              be used by PMIx. Defaults to not being set.

       PMIxFenceBarrier={true|false}
              Define whether to fence inter-node communication for data collection.   Default  is
              "false". See also PMIxCollFence.

       PMIxNetDevicesUCX=<device type>
              Type of network device to use for communication.  Defaults to not being set.

       PMIxTimeout=<time>
              The  maximum  time  (in  seconds)  allowed  for communication between hosts to take
              place. Defaults to 300 seconds.

       PMIxTlsUCX=<tl1>[,<tl2>...]
              Sets the UCX_TLS variable which restricts  the  transports  to  use.  The  accepted
              values  are  defined  in  the UCX documentation and may vary between installations.
              Multiple values can be set and must be separated by commas.  If not set, UCX  tries
              to  use  all  available  transports  and  selects  the best ones according to their
              performance capabilities and scale.  Defaults to not being set.

COPYING

       Copyright (C) 2022 SchedMD LLC.

       This  file  is  part  of  Slurm,  a  resource  management  program.   For   details,   see
       <https://slurm.schedmd.com/>.

       Slurm  is  free  software; you can redistribute it and/or modify it under the terms of the
       GNU General Public License as published by the Free Software Foundation; either version  2
       of the License, or (at your option) any later version.

       Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
       even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
       GNU General Public License for more details.

SEE ALSO

       slurm.conf(5)