<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<p>Folks,</p>
<p>Please find the minutes <a moz-do-not-send="true" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Software_Meeting,_August_17,_2021#Minutes">here</a>
and below.</p>
<p> -- Mark</p>
<p> __________________________________</p>
<p>
</p>
<div id="globalWrapper">
<div id="column-content">
<div id="content" class="mw-body" role="main">
<h2 id="firstHeading" class="firstHeading" lang="en"><span dir="auto">GlueX Software Meeting, August 17, 2021, </span><span class="mw-headline" id="Minutes">Minutes</span></h2>
<div id="bodyContent" class="mw-body-content">
<div id="mw-content-text" dir="ltr" class="mw-content-ltr" lang="en">
<p>Present: Alex Austregesilo, Nathan Brei, Sean Dobbs,
Sergey Furletov, Nathaniel Hoffman, Mark Ito (chair),
Igal Jaegle, Naomi Jarvis, Torri Jeske, Richard Jones,
David Lawrence, Alison LaDuke, Zisis Papandreou, Simon
Taylor, Tyler Viducic, Jon Zarling
</p>
<p>There is a <a rel="nofollow" class="external text" href="https://bluejeans.com/s/RgU@pTgb256">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://mailman.jlab.org/pipermail/halld-offline/2021-August/008601.html">New
version set: 4.44.0</a> This is the latest and was
released a week ago.</li>
<li> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld-offline/2021-August/008604.html">Dirac++
library now builds as standalone using cmake</a>
This is a major structural change to the layout of the
Diracxx directory. It requires two new packages,
python3-devel and boost-python36-devel, that many of
us did not have installed heretofore.</li>
<li> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld-offline/2021-August/008605.html">move
to new work disk</a> This is happening today.</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,_July_20,_2021#Minutes" title="GlueX Software Meeting, July 20, 2021">minutes
from the meeting on July 20</a>.
</p>
<p>On halld_recon issue #537, <a rel="nofollow" class="external text" href="https://github.com/JeffersonLab/halld_recon/issues/537">Problems
with photon energies in MC samples</a>, Sean noted
that Richard has merged in Sean's changes to address
parts of the problem. If further tests are done and
succeed, we may consider back-ported this fix to older
reconstruction versions.
</p>
<p>Also Sean has looked as some of the random trigger
files. He sees instances where the correct counter
recorded but the wrong tagged beam energy. He has a
script that will correct the energy and plans to
re-write corrected copies of these files.
</p>
<p>Richard asked about whether there is a system at the
Lab for coordinating file transfer, starting from the
tape library on to off-site locations. There does not
seem to be an end-to-end solution. David suggested
submitting a Service Now Incident Report (SNIR).
</p>
<p>Mark reported that he and Alex discussed the location
of files brought back to the Lab from the HPC centers.
They concluded that the current use of volatile and
cache is giving acceptable performance.
</p>
<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,_August_10,_2021#Minutes" title="HDGeant4 Meeting, August 10, 2021">minutes from
the HDGeant4 meeting on August 10</a> with very little
comment or discussion.
</p>
<h3><span class="mw-headline" id="FAQ_of_the_Fortnight:_What_is_the_difference_between_a_clone_and_a_fork.3F">FAQ
of the Fortnight: What is the difference between a
clone and a fork?</span></h3>
<p>Mark made some remarks about <a href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_FAQ#What_is_the_difference_between_a_clone_and_a_fork.3F" title="GlueX Offline FAQ">this FAQ</a>. A fork is a
clone from a GitHub repository to another GitHub
repository, with GitHub-specific features added. Find
the explanation at 27:45 in the recording. He described
the difference and demonstrated the defaults in how
GitHub presents source and target repo/branch
combinations when a pull request is composed.
</p>
<h3><span class="mw-headline" id="More_on_using_GCC_8">More
on using GCC 8</span></h3>
<p>Mark has been successful building the GlueX software
using Geant4 10.06 and GCC 8 using three different
methods:
</p>
<ul>
<li> GCC 8 in a CentOS 7 Container using Developers
Toolset 8</li>
<li> GCC 8 in a CentOS 8 Container</li>
<li> GCC 8 module installed on the farm</li>
</ul>
<p>The first was discussed at the last Software Meeting
and announced in <a rel="nofollow" class="external
text" href="https://mailman.jlab.org/pipermail/halld-offline/2021-July/008587.html">an
email message</a>.
</p>
<p>There are <a href="https://halldweb.jlab.org/wiki/index.php/Offline_HOWTO_List#GlueX_Software_with_GCC_8" title="Offline HOWTO List">HOWTOs for each of these
approaches</a>.
</p>
<h3><span class="mw-headline" id="Histogramming_Using_Uproot_and_Our_Flat_Tree_Output">Histogramming
Using Uproot and Our Flat Tree Output</span></h3>
<p>Jon introduced <b>gluupy</b>, a system for fast
histogramming of <b>Gl</b>ueX data using <b>Up</b>root
and <b>Py</b>thon.
</p>
<ul>
<li> Speed comes principally from putting trees in large
Numpy arrays.</li>
<li> Filling of Numpy arrays from ROOT trees is
facilitated by Uproot.</li>
<li> ROOT functionality accessed from Python with
PyROOT.</li>
</ul>
<p>The goal is to reduce the time of execution and
overhead of setting up an iteration of an analysis.
Progress in refining an analysis therefore happens more
quickly and perhaps more comprehensively as well (more
things can be tried).
</p>
<p>The walked us through a complete example of an analysis
of η→π<sup>0</sup>π<sup>0</sup>π<sup>0</sup>.
</p>
<p>Please see <a rel="nofollow" class="external text" href="https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=5237">his
slides</a> for details and find his presentation
starting at 47:50 in the recording. The code is
available in the hd_utilities repository.
</p>
<h3><span class="mw-headline" id="Maintaining_the_Online_halld_recon">Maintaining
the Online halld_recon</span></h3>
<p>David and Sergey proposed new approach to maintaining
the build of halld_recon used for various purposes
during data taking. Traditionally the build was done on
disks resident in the Counting House to insulate us from
network outages and was maintained "by hand." Instances
where the network caused difficulties have turned out to
be rare and so we might want to use a variant of the
system used in the offline builds to take advantage of
the effort already being expended in maintaining them,
even though that is done on a network mounted disk in
the Computer Center. Alex pointed out that we upgrade
the online halld_recon only seldom, for stability during
the run. Mark mentioned we could go to a system where a
version set file is used to choose the running version,
so upgrades can proceed in parallel with use of a
production version, and any switch to a new build can be
reversed instantly if problems arise.
</p>
<p>Alex agreed to call a meeting to discuss these issues
with David, Sergey, and Mark.
</p>
</div>
<br>
</div>
</div>
</div>
</div>
</body>
</html>