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<p>Folks,</p>
<p>Find the minutes below and at
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_January_18,_2017#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_January_18,_2017#Minutes</a>
.</p>
<p> -- Mark</p>
<p>____________________</p>
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<h2 id="firstHeading" class="firstHeading" style="font-weight:
bold;" lang="en"><span dir="auto">GlueX Offline Meeting,
January 18, 2017, </span><span class="mw-headline"
id="Minutes">Minutes</span></h2>
<div id="bodyContent" class="mw-body-content">
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lang="en">
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Present:</p>
<ul style="list-style-type: square;">
<li><b>FIU</b>: Mahmoud Kamel</li>
<li><b>JLab</b>: Alexander Austregesilo, Nathan Baltzell,
Alex Barnes, Thomas Britton, Brad Cannon, Mark Ito
(chair), Nathan Sparks, Kurt Strosahl, Simon Taylor,
Beni Zihlmann</li>
<li><b>MIT</b>: Cristiano Fanelli</li>
<li><b>NU</b>: Sean Dobbs</li>
<li><b>UConn</b>: Richard Jones + 2</li>
<li><b>W&M</b>: Justin Stevens</li>
</ul>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">There is a<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://bluejeans.com/s/tgAip/" style="color:
inherit !important; background: transparent; padding:
0px !important; text-decoration: inherit !important;">recording
of this meeting</a><span class="Apple-converted-space"> </span>on
the BlueJeans site.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Announcements">Announcements</span></h3>
<ol>
<li><b>Backups of the RCDB database in SQLite</b><span
class="Apple-converted-space"> </span>form are now
being kept on the write through cache, in
/cache/halld/home/gluex/rcdb_sqlite/. See<span
class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002573.html"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">Mark's email</a><span
class="Apple-converted-space"> </span>for more
details.</li>
<li><b>Development of a wrapper for signal MC generation</b>.
Thomas has written scripts to wrap the basic steps of
signal Monte Carlo generation. One can specify the
number of events, the .input file to use for genr8, and
jobs will be submitted via SWIF. Paul thought the the
average user would find this useful. Mark suggested that
the code could be version controlled with the<span
class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/hd_utilities"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">hd_utilities repository</a><span
class="Apple-converted-space"> </span>on GitHub.</li>
<li><b>More Lustre space</b>. Mark reported that our total
Lustre space has been increased from a quota of 200 TB
to 250 TB. See<span class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002594.html"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">his email</a><span
class="Apple-converted-space"> </span>for a few more
details.</li>
</ol>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Lustre_system_status">Lustre
system status</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Kurt Strosahl, of JLab SciComp,
dropped by to give us a report on the recent problems with
the<span class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="https://en.wikipedia.org/wiki/Lustre_%28file_system%29"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">Lustre file system</a>. This has
affected our work, cache, and volatile directories. Lustre
aggregates multiple partitions on multiple raid arrays,
"block devices" or "Object Store Targets (OSTs), and
presents to users a view of one large disk partition.
There are redundant metadata systems to keep track of
which files are where.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">On New Year's Day, due to Infiniband
problems, a fail-over from one metadata system to the
other was initiated mistakenly. In the confusion both
systems tried to mount a few of the OSTs causing
corruption of the metadata for five of the 74. This was
the first time a fail-over has occurred for a production
system at JLab. Intel and SciComp have been working
together to recover the metadata. The underlying files
appear to be OK, but without the metadata they cannot be
accessed. So far, metadata for four of the five OSTs has
been repaired and it appears that their files have
reappeared intact. This work has been going on for over
two weeks now; there is no definite estimate on when the
last OST will be recovered. Fail-over has been inhibited
for now.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We asked Kurt about recent troubles
with ifarm1102. That particular nodes has been having
issues with its Infiniband interface and has now been
removed from the rotation of ifarm machines.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline"
id="Review_of_minutes_from_the_last_meeting">Review of
minutes from the last meeting</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We went over the<span
class="Apple-converted-space"> </span><a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_December_21,_2016#Minutes"
title="GlueX Offline Meeting, December 21, 2016"
style="color: rgb(85, 34, 0); background: transparent;
padding: 0px !important; text-decoration: underline;">minutes
from December<span class="Apple-converted-space"> </span></a>(all)</p>
<ul style="list-style-type: square;">
<li>The problem with reading data with multiple threads
turn out indeed to be from corrupted data. There was an
issue with the raid arrays in the counting room.</li>
<li>Sean has had further discussions on how we handle HDDS
XML files. There is a plan now.</li>
<li>Mark will ask about getting us an update on the OSG
appliance.</li>
</ul>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Launches">Launches</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Alex A. gave the report.</p>
<h4 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline"
id="2016-10_offline_monitoring_ver02">2016-10 offline
monitoring ver02</span></h4>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Alex wanted to start this before the
break, but calibration were not ready. Instead processing
started the first week of January, but since there was not
a lot of data in the run, it finished in a week. The
gxproj1 account was used. There were some minor problems
with the post processing scripts that have now been fixed.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We are waiting for new calibration
results before starting ver03, perhaps sometime next week.
There was an issue with the propagation delay calibration
for the TOF that has now been resolved and there are
on-going efforts with BCAL and FCAL calibrations. The
monitoring launch gives us a check on the quality of the
calibrations for the entire running period.</p>
<h4 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="2016-02_analysis_launch_ver05">2016-02
analysis launch ver05</span></h4>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">This launch started before the break.
Jobs are running with only six threads. Large variation in
execution time and peak memory use has been observed. The
cause has been traced to a few channels what require many
photons (e. g., 3π<sup>0</sup>) that can generate huge
numbers of combinations and stop progress on a single
thread. Several solutions were discussed, including
re-writing parts of the analysis library and cutting off
processing for events that generate too many combinations.
In addition, in the future the list of plugins may get
trimmed. This last effort took the philosophy of running
"everything" to see how many channels we can reasonably
get through.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Sim_1.2">Sim 1.2</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Mark reported that the 50 k jobs that
have been submitted are going through very slowly.
Processing started in the middle of the break and is only
20% done and this batch is only 20% of the total we
planned to simulate. The processing time is dominated by
the generation of electromagnetic background independently
for each event. After some discussion of the purpose of
the resulting data set, we decided to re-launch the effort
without generation of E&M background. The data should
still be useful for studying efficiency/acceptance.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="HDGeant.2FHDGeant4_Update">HDGeant/HDGeant4
Update</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Richard gave us an update on the
development effort.</p>
<ul style="list-style-type: square;">
<li>He is doing a tag-by-tag comparison of the output from
HDGeant ("G3" for our purposes) and HDGeant4 ("G4"),
comparing both truth and hit information. For 90% of the
discrepancies he finds it is the new G4 code that needs
fixing, but the other 10% come from G3 errors, mostly in
truth information that is not looked at as often.</li>
<li>To do the comparison he has developed a new tool,
hddm-root, that creates a ROOT tree auto-magically
directly from an HDDM file. This allows quick
histogramming of quantities for comparison.</li>
<li>Detectors where agreement has been verified: CDC, FDC,
BCAL, FCAL, TOF, tagger, pair spectrometer (course and
fine), triplet polarimeter.</li>
<li>The triplet polarimeter simulation was adopted from
code from Mike Dugger and was originally implemented in
G4, but has also been back-ported to G3.</li>
<li>To test the TPOL simulation, a new card has been
introduced, GENB[?], that will track beam photons down
the beamline from the radiator. It has three modes:
pre-coll, post-coll, and post-conv which end tracking at
the collimator, at the converter, and on through to the
TPOL respectively. The generated particle information
can be written out in HDDM format and serve as input to
either G3 or G4, just as for any other of our event
generators.</li>
<li>The coherent bremsstrahlung generator has been
implemented in G4 and compared to that of G3.</li>
<li>"Fake" tagger hits are now being generated in G4 in
the same manner as was done in G3. Also a new tag
RFTime[?] has been introduced. It is a single time that
sets the "true" phase of the RF used in the simulation.</li>
<li>Other detectors implemented: the DIRC, the MWPC (for
the CPP experiment), and for completeness the gas RICH,
the gas Cerenkov, and the UPV.</li>
<li>The MCTRAJECTORY card has been implemented in G4 and
its implementation in G3 fixed. This allows output of
position information for particle birth, death, and/or
points in between for primary and/or secondary particles
in a variety of combinations of those items.</li>
<li>The following G3 cards have been implemented in G4.
The secretary will refer the reader to the documentation
in the sample control.in for definitions of most of
these.
<ul style="list-style-type: square;">
<li>KINE</li>
<li>SCAT</li>
<li>TARGET</li>
<li>BGGATE</li>
<li>BGRATE</li>
</ul>
</li>
<li>The following cards will not be implemented in G4
<ul style="list-style-type: square;">
<li>CUTS</li>
<li>SWITCH
<ul style="list-style-type: square;">
<li>CUTS and SWITCH do not fit into the Geant4
design philosophy</li>
</ul>
</li>
<li>GELHAD
<ul style="list-style-type: square;">
<li>photonuclear interactions are now provided
natively in Geant4</li>
</ul>
</li>
</ul>
</li>
<li>The following cards are being implemented now:
<ul style="list-style-type: square;">
<li>HADR
<ul style="list-style-type: square;">
<li>The meaning in G4 has been modified to control
turning on/off all hadronic interaction
processes to save users the bother of doing so
one by one</li>
</ul>
</li>
<li>CKOV</li>
<li>LABS</li>
<li>NOSEC</li>
<li>AUTO</li>
<li>BFIELD_MAP</li>
<li>PSFIELD_MAP</li>
<li>SAVEHIT</li>
<li>SHOWERS_IN_COLLIMATOR</li>
<li>DRIFT_CLUSTERS</li>
<li>MULS</li>
<li>BREMS</li>
<li>COMPT</li>
<li>LOSS</li>
<li>PAIR</li>
<li>DECAY</li>
<li>DRAY</li>
</ul>
</li>
</ul>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Beni will describe the scheme he
implemented in G3 to preserve the identify of secondary
particles and transmit the description to Richard.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Performance remains an issue but is
not an area of focus at this stage. Richard has seen a
slow-down of a factor of 24 per thread going from G3 to
G4. At this point G4 is generating two-orders of magnitude
more secondary particles, mostly neutrons, compared to G3.
A simple kinetic energy threshold adjustment did not make
much of a difference.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Sean made a couple of comments:</p>
<ol>
<li>The problem Richard discovered with missing TDC hits
in the BCAL has been traced to the generation of
digi-hits for the BCAL. CCDB constants had to be
adjusted to bring those hits back.</li>
<li>Caution should be used with the current pair
spectrometer field map called for the in CCDB. It is
only a preliminary rough guess.</li>
</ol>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Mark needs to create a standard build
of G4.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Richard requested that if folks have
problems, questions, or suggestions, they should log an<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://github.com/rjones30/HDGeant4/issues"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">issue on GitHub</a>.</p>
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