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<p class="MsoNormal">HI Craig,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Its not essential to use the pmix lib used to build the SLURM pmix plugin but it does reduce likelihood of problems.<o:p></o:p></p>
<p class="MsoNormal">I don’t know how, but there is some way that the admin installing SLURM can “name” the available pmix –mpi options.<o:p></o:p></p>
<p class="MsoNormal">For instance on one of our systems, the admin has built multiple variants of the pmix plugin:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="p1"><span class="s1">MPI plugin types are...</span></p>
<p class="p1"><span class="apple-tab-span"> </span><span class="s1">cray_shasta</span></p>
<p class="p1"><span class="apple-tab-span"> </span><span class="s1">none</span></p>
<p class="p1"><span class="apple-tab-span"> </span><span class="s1">pmi2</span></p>
<p class="p1"><span class="apple-tab-span"> </span><span class="s1">pmix</span></p>
<p class="p1"><span class="s1">specific pmix plugin versions available: pmix_v2,pmix_v3,pmix_v314,pmix_v4,pmix_v422</span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This naming convention has helped us with “decoupling” building of Open MPI from SLURM build, but does mean some coordination with the sys admins.<o:p></o:p></p>
<p class="MsoNormal">We’re using SLURM 22.05.6<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hope this helps,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Howard<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">slurm-users <slurm-users-bounces@lists.schedmd.com> on behalf of Craig <cfreese@super.org><br>
<b>Reply-To: </b>Slurm User Community List <slurm-users@lists.schedmd.com><br>
<b>Date: </b>Monday, March 27, 2023 at 2:01 PM<br>
<b>To: </b>"slurm-users@lists.schedmd.com" <slurm-users@lists.schedmd.com><br>
<b>Subject: </b>Re: [slurm-users] [EXTERNAL] OpenMPI and Slurm clarification?<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">conf.log...<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal">checking if user requested PMI support<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">result: no<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">checking if user requested internal PMIx support(yes)<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">result: no<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">checking for pmix.h in /usr<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">result: not found<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">checking for pmix.h in /usr/include<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">result: not found<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">WARNING: discovered external PMIx version is less than internal version 3.x<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">WARNING: using internal PMIx<o:p></o:p></p>
</div>
</blockquote>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">So is looks like it used the internal version (which is what I was aiming for) and that's ok by me since it seems to be working, but if I'm really supposed to be using the same one that SLURM used then I'm gonna have to figure out a way
to determine what that was/is.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">On 3/27/23 15:28, Pritchard Jr., Howard wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">HI Craig,</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Your use of the –with-pmix on the open mpi configure line is important. Without any args to this configure option open mpi configure will first check if there’s an external pmix which is newer than the one that is included in the openmpi
release tarball. If it is not, the internal pmix is built.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">You can check in the config.log whether the internal PMix or an external one was used.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">If you want to be extra careful, find the location of the PMIx v3 used to build the SLURM PMIx plugin, and then rebuild your open mpi 4.1.5 with</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">./configure … --with-pmix=path_to_pmix_used_for_slurm_pmix_plugin_build ….</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">But you may be okay without doing this. You can check this by running your open mpi job with</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">srun –mpi=pmix_v3 -N2 foo</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">and see if it behaves as expected.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">I’m not sure what the “openmpi” result from srun –mpi=list is about.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Howard</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">slurm-users
</span><a href="mailto:slurm-users-bounces@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users-bounces@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"> on behalf of Craig
</span><a href="mailto:cfreese@super.org"><span style="font-size:12.0pt"><cfreese@super.org></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Reply-To: </b>Slurm User Community List </span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Date: </b>Monday, March 27, 2023 at 12:54 PM<br>
<b>To: </b></span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt">"slurm-users@lists.schedmd.com"</span></a><span style="font-size:12.0pt;color:black">
</span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Subject: </b>Re: [slurm-users] [EXTERNAL] OpenMPI and Slurm clarification?</span></p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">srun: MPI types are...</p>
</div>
<div>
<p class="MsoNormal">srun: none</p>
</div>
<div>
<p class="MsoNormal">srun: openmpi</p>
</div>
<div>
<p class="MsoNormal">srun: pmix_v3</p>
</div>
<div>
<p class="MsoNormal">srun: pmi2</p>
</div>
<div>
<p class="MsoNormal">srun: pmix</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">but I'm not sure that tells me much about how I am supposed to be building OpenMPI?</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">On 3/27/23 14:41, Pritchard Jr., Howard wrote:</p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">HI Craig,</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">If you run</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">srun –mpi=list</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">what does slurm report?</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">That will help in determining what argument you want to supply for the –mpi srun option.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Howard</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">slurm-users
</span><a href="mailto:slurm-users-bounces@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users-bounces@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"> on behalf of Craig
</span><a href="mailto:cfreese@super.org"><span style="font-size:12.0pt"><cfreese@super.org></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Reply-To: </b>Slurm User Community List </span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Date: </b>Monday, March 27, 2023 at 12:38 PM<br>
<b>To: </b></span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt">"slurm-users@lists.schedmd.com"</span></a><span style="font-size:12.0pt;color:black">
</span><a href="mailto:slurm-users@lists.schedmd.com"><span style="font-size:12.0pt"><slurm-users@lists.schedmd.com></span></a><span style="font-size:12.0pt;color:black"><br>
<b>Subject: </b>[EXTERNAL] [slurm-users] OpenMPI and Slurm clarification?</span></p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><br>
Can someone please clarify the "best practices" for building OpenMPI compatible with Slurm?<br>
<br>
<a href="https://urldefense.com/v3/__https:/slurm.schedmd.com/mpi_guide.html*open_mpi__;Iw!!Bt8fGhp8LhKGRg!Cb86a2IwxgqfT5fv1_eEByDpAyhly3ZdN6Wwl7Wod9FRPx9HBpvFVojIRgu5oSpti_3jOXhNyvJqEMGs$">https://slurm.schedmd.com/mpi_guide.html#open_mpi</a> tells me what
I _can_ do but I'm unclear as to what I _should_ do. <br>
<br>
I've built OpenMPI 4.1.5 with: --with-pmix --with-libevent=internal --with-hwloc=internal --with-slurm. If I run an MPI program on my cluster (slurm 18.08.8) with "srun -N2 foo" it seems to work fine. (slurm.conf has MpiDefault=pmix).<br>
<br>
If I "srun --mpi=openmpi -N2 foo" it chokes with:</p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">OPAL_ERROR: Unreachable in file ../../../../../opal/mca/pmix/pmix3/pmix3x_client.c at line 112<br>
-------------------------------------------------------------------------------------------------------------------<br>
This application appears to have been direct launched using "srun",<br>
but OMPI was not build with SLURM's PMI support and therefore cannot<br>
execute. There are several options for building PMI support under<br>
SLURM, depending upon the SLURM version you are using:<br>
<br>
version 16.05 or later: you can use SLURM's PMIx support. THis<br>
require that you configure and uild SLURM --with-pmix.<br>
.<br>
.<br>
.</p>
</blockquote>
<p class="MsoNormal"><br>
So I guess the question is, what is the "right" way to build OpenMPI with Slurm. Is the fact that my non-Slurm pmix works "correct" or am I just getting lucky that the various software I have just happens to be compatible. If I build OpenMPI am I supposed
to use Slurm's pmix/libevent/hwloc or is that optional. If it's optional when/why might I choose to do so. If I need Slurm's versions is there some way to find which pmix/libevent/hwloc my current Slurm install is using? Note: my sysadmins are not going
to be helpful as they think Slurm 18 and OpenMPI 4.0.2a is adequate for users' needs :^(.
<br>
<br>
I like the idea of _not_ tying my OpenMPI to the installed Slurm just in case our support people ever decide to upgrade system software.<br>
<br>
Thanks.</p>
<p> </p>
</blockquote>
<p> </p>
</blockquote>
<p><o:p> </o:p></p>
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