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<p>Friends,</p>
<p>Please find the minutes <a moz-do-not-send="true" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Software_Meeting,_October_25,_2021,_2021#Minutes">here</a>
and below.</p>
<p> -- Mark</p>
<p> __________________________________</p>
<p>
</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span dir="auto">GlueX Software Meeting, October 25, 2021,
</span><span class="mw-headline" id="Minutes">Minutes</span></h2>
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<p>Present: Alex Austregesilo, Thomas Britton, Sean
Dobbs, Mark Ito (chair), Igal Jaegle, Richard
Jones, David Lawrence, Simon Taylor, Beni Zihlmann
</p>
<p>There is a <a rel="nofollow" class="external
text" href="https://bluejeans.com/s/NkHJt0V1qUu/">recording
of this meeting</a>. Log into the <a rel="nofollow" class="external text" href="https://jlab.bluejeans.com">BlueJeans site</a>
first to gain access (use your JLab credentials).
</p>
<h3><span class="mw-headline" id="Announcements">Announcements</span></h3>
<ol>
<li> <a rel="nofollow" class="external text" href="https://halldweb.jlab.org/talks/2021/%5bOSG-Users%5d%20Power%20off%20of%20scosg16.pdf">Power
off of scosg16</a>. scosg16.jlab.org is going
away. It will be replaced by scosg20.jlab.org as
our OSG submit node.
<ul>
<li> scosg20 is two-factored. Use your JLab
two-factor login method (i.e., the same as
you use to log into hallgw.jlab.org, e.g.,
MobilePASS) to login in.</li>
<li> scosg20 is not a GLOBUS endpoint, as
scosg16 was. Use a Data Transfer Node (DTN)
instead. Ask the computer center for access
if you do not have it already.</li>
</ul>
</li>
<li> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/jlab-scicomp-briefs/2021q4/000867.html">Compute
Farm Updates</a> Nodes on the JLab farm will
transitioning from CentOS 7.7 to 7.9 over the
next months. As <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld-offline/2021-October/008665.html">announced
last week</a>, CentOS 7.9 nodes with be
assigned the BMS_OSNAME corresponding to 7.7 for
the time being.</li>
<li> <b>CentOS Stream 8</b>. Richard alerted us
to the news that CERN and Fermilab are heading
in the direction of CentOS Stream 8 as the next
generation scientific computing platform. From <a rel="nofollow" class="external text" href="https://halldweb.jlab.org/talks/2021/20211018-itum34.pdf">slides
shown at a CERN IT Technical-Users Meeting</a>:
"Going forward, we propose to target CentOS
Stream 8 as the standard distribution for
experiments."
<ul>
<li> David expressed the concern that with
CentOS Stream streaming ahead, there might
be OS-dependent gotcha's not captured by our
versioning scheme. Richard proposed
containers as a way around that. He also
mentioned that the CERN/Fermi folks have
operational experience with Stream without
major difficulties, evidence of the lack of
gotcha's.</li>
<li> David endorsed the idea of running in
containers on the JLab farm. He pointed out
that we already run containerized on all of
the off-site platforms we use. Richard
remarked that an added benefit of
standardizing on containers is that non-JLab
folks (e.g., Richard) could reproduce the OS
exactly when troubleshooting reported
problems, and not have to log into JLab to
get the right OS.</li>
</ul>
</li>
</ol>
<h3><span class="mw-headline" id="Review_of_Minutes_from_the_Last_Software_Meeting">Review
of Minutes from the Last Software Meeting</span></h3>
<p>We went over the <a href="https://halldweb.jlab.org/wiki/index.php/GlueX_Software_Meeting,_October_11,_2021#Minutes" title="GlueX Software Meeting, October 11, 2021">minutes
from the meeting on October 11th</a>.
</p>
<h4><span class="mw-headline" id="Doxygen_and_Documentation">Doxygen and
Documentation</span></h4>
<p>Beni had been exploring the features of Doxygen
by adding comments to the TOF and start counter
code. He thinks there is a lot of promise in using
Doxygen, but needs to learn the system a bit more
before rendering judgment. He will give us a
summary of what he has learned once he is farther
along.
</p>
<p>Richard brought up the use of Doxygen at an EIC
simulation meeting with Makoto Asai in attendance.
The feeling of the participants was that a PDF
note was the best choice for the primary
documentation vehicle. Doxygen was useful, but
mainly to a small core of developers. This despite
Geant4 having extensive Doxygen-oriented comments.
</p>
<p>Having a summary of purpose and methods at the
top of source files, using Doxygen syntax seems to
be a consensus best practice.
</p>
<h4><span class="mw-headline" id="DL1MCTrigger_Crashes_With_mysql_rcdb.2Fccdb">DL1MCTrigger
Crashes With mysql rcdb/ccdb</span></h4>
<p>We had more discussion of <a rel="nofollow" class="external text" href="https://github.com/JeffersonLab/halld_recon/issues/81">halld_recon
Issue #81</a>.
</p>
<ul>
<li> Alex had posted an example that will produce
the error reliably. Interestingly, it only
occurs for SQLite CCDB files on a raw data file.
The original post reported the bug in
simulation, and only when using a MySQL server
for CCDB. Alex example only has trouble when
running multi-threaded.</li>
<li> There may be two different issues here.</li>
<li> Richard speculated that there is some sort of
race condition when running multi-threaded.</li>
<li> Simon tried to reproduce the error under
Valgrind, without success (i.e., it worked).</li>
</ul>
<h3><span class="mw-headline" id="Review_of_Minutes_from_the_Last_HDGeant4_Meeting">Review
of Minutes from the Last HDGeant4 Meeting</span></h3>
<p>We went over the <a href="https://halldweb.jlab.org/wiki/index.php/HDGeant4_Meeting,_October_18,_2021#Minutes" title="HDGeant4 Meeting, October 18, 2021">minutes
from the meeting on October 18</a>. Igal will
enforce an upper limit on the single-block FCAL
energy in mcsmear to avoid values in excess of 8
GeV.
</p>
<h3><span class="mw-headline" id="FAQ_of_the_Fortnight:_What_are_.22directory_tags.3F.22">FAQ
of the Fortnight: What are "directory tags?"</span></h3>
<p>Mark led us through the <a href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_FAQ#What_are_.22directory_tags.3F.22" title="GlueX Offline FAQ">FAQ</a>.
</p>
<h3><span class="mw-headline" id="Package_Structure">Package
Structure</span></h3>
<p>Mark led us through a series of <a rel="nofollow" class="external text" href="https://halldweb.jlab.org/talks/2021/package_structure.pdf">diagrams</a>
illustrating the dependency structure of our
software packages along with a proposal for a new
structure. Find his explanation starting at 55:54
in the recording.
</p>
<p>He proposes a structure such that the simulation
code (halld_sim and hdgeant4) does not depend on
the "reconstruction" code (halld_recon). This
should be possible since simulation is performed
before reconstruction, everywhere and always. The
current structure has halld_sim and hdgeant4
dependent on halld_recon, not because of the
details of reconstruction, but due to other
support functions that happen to live in the
halld_recon repository, in particular I/O routines
and magnetic-field handling. </p>
<p>To obtain independence of simulation from
reconstruction, he proposed a new package,
hd_interface, that captures all code from
halld_recon upon which simulation depends. The
weakness in the scheme is that a naive capture of
source files from halld_recon into hd_interface,
while allowing a build of halld_sim and hdgeant4
independent of halld_recon, likely gives an
interface library that impacts reconstruction. The
impact is clearly less than that which comes with
dependence on the whole of halld_recon, still it
diminishes the utility of the new interface
library. The extent of the diminution needs review
going forward.
</p>
<h3><span class="mw-headline" id="Action_Item_Review">Action Item Review</span></h3>
<ol>
<li> Create a Wiki page of Doxygen links. (Mark)</li>
<li> Add Alex to the gluex_admin team on GitHub.
(Mark)</li>
<li> Add non-privileged pull-request-re-test
procedure to the FAQ.</li>
<li> Figure out why Beni's Doxygen-related pull
request does not return a result from the
automatic test.</li>
</ol>
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