<html>#2287: add OpenMPI env vars to notebook to avoid warning messages du to vader library in containers
<table style='border-spacing: 1ex 0pt; '>
<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td>EinsteinToolkit Virtual Machine</td></tr>
</table>
<p>Running in a Docker container based on Ubuntu 18.04 I am now getting error message like this</p>
<div class="codehilite"><pre><span></span>[ekohaes8:26785] Read -1, expected 313632, errno = 1
</pre></div>
<p>by the hundreds (this is using Ubuntu 18.04 rather than 16.04 so may only happen for new versions of OpenMPI. The OpenMPI ticket referenced below mentions this to happen on at least OpenMPI 4.0 and 3.1.3). This is apparently known: <a data-is-external-link="true" href="https://github.com/open-mpi/ompi/issues/4948" rel="nofollow">https://github.com/open-mpi/ompi/issues/4948</a> with the workaround being to set an env variables (or setting in the .conf file in $HOME):</p>
<div class="codehilite"><pre><span></span>export OMPI_MCA_btl_vader_single_copy_mechanism=none
</pre></div>
<p>This can also depend on the docker version used it would seem as <code>docker run --cap-add=SYS_PTRACE ...</code> is offered as a host-side workaround.</p>
<p>Note that the simulation itself is unaffected (other than producing very many warnings).</p>
<p>This happened to at least one person who reported this on the mailing list: <a data-is-external-link="true" href="http://lists.einsteintoolkit.org/pipermail/users/2019-September/007046.html" rel="nofollow">http://lists.einsteintoolkit.org/pipermail/users/2019-September/007046.html</a></p>
<p>This was reported in <a data-is-external-link="true" href="https://bitbucket.org/einsteintoolkit/tickets/issues/2234/trouble-in-the-tutorial-server#comment-51221094" rel="nofollow">https://bitbucket.org/einsteintoolkit/tickets/issues/2234/trouble-in-the-tutorial-server#comment-51221094</a> but reverted as not directly applicable to the jupyter tutorial server. However since this now seems to happen to regular users I would like to add this setting to the tutorial notebook.</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2287/add-openmpi-env-vars-to-notebook-to-avoid'>https://bitbucket.org/einsteintoolkit/tickets/issues/2287/add-openmpi-env-vars-to-notebook-to-avoid</a></p>
</html>