[Halld-offline] Software Meeting Minutes, October 30, 2018

Fri Nov 2 17:18:14 EDT 2018

Folks,

Please find the minutes here 
<https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_October_30,_2018#Minutes> 
and below.

   -- Mark

_________________________________________

  GlueX Offline Meeting, October 30, 2018, Minutes

Present:

  * *CMU: * Hao Li, Reinhard Schumacher
  * *FSU: * Sean Dobbs
  * *JLab: * Ashley Ernst, Mark Ito (chair), David Lawrence, Simon
    Taylor, Beni Zihlmann
  * *W&M: * Justin Stevens

There is a recording of this meeting <https://bluejeans.com/s/xuYcn/> on 
the BlueJeans site. Use your JLab credentials to access it.

      Announcements

 1. New release of halld_sim: version 3.6.0
    <https://mailman.jlab.org/pipermail/halld-offline/2018-October/003403.html>.
    Released October 22. Has changes from Colin Gleason for
    amplitude-based generators.
 2. New bug-fix release: halld_sim 3.1.1
    <https://mailman.jlab.org/pipermail/halld-offline/2018-October/003405.html>.
    A special release to get genEtaRegge going.

      Review of minutes from the October 16 meeting

We reviewed the minutes 
<https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Software_Meeting,_October_16,_2018#Minutes>. 

  * *Computing Review*. Curtis Meyer has circulated a list of slide
    titles he proposes for the Hall D presentation. David gave feedback.
    Now only adding contest remains.

      Monitoring launch ver 18 @ NERSC

David reviewed his recent email 
<https://mailman.jlab.org/pipermail/halld/2018-October/000645.html>.

  * The monitoring launch at NERSC is mostly finished. There are a few
    jobs where the 271 thread finished successfully, but the 272nd
    won't. This seems to happen with particular input files. These jobs
    were tried on the gluons and ran without a problem. However, recall
    that they ran on KNL architecture at NERSC. David is requesting an
    interactive node at NERSC to do a test.
  * Bryan Hess has found a few more places in the network where the MTU
    had room for increase. He is curious about how the new configuration
    will perform.
  * The problem with missing cache files causing jobs to hang remains,
    likely due to deletion from the auto-cache cleaner. David will
    pursue solutions with Chris Larrieu.
  * David is thinking about what to do next. Sean is in favor of a
    monitoring launch using 10 files per run dispersed throughout the
    Spring 2018 run. David told Bryan that he is thinking of firing up
    another launch at the end of next week.
  * Beni asked about tape robot problems. David has not seen any lately,
    but heavy tape use during data taking may not have occurred recently.
  * David and Mark will discuss the version XML file that David is using
    on NERSC.

      What I learned at BRNMW 2018

David attended the Basic Research Needs for Microelectronics Workshop 
last week. Turns out he learned quite a lot, from topics like DNA memory 
technology to others like hotel meeting room door sound standards. 
Please see his slides 
<https://halldweb.jlab.org/wiki/images/f/f8/20181030_BRNMW2018.pdf> for 
the details.

      Events lost due to vertex fit for Lambda

Hao gave us a detailed look at the problem and proposed solutions to the 
issue where kinematic fits with vertex constraints do not converge. See 
his slides 
<https://halldweb.jlab.org/DocDB/0038/003812/001/Offline_software_meeting_Oct_30_HaoLi.pdf> 
for the details.

  * He described the channel where the problem seems especially severe,
    γp→ΛΛ̅p.
  * He sees a deficit in the π^− lab polar angle at around 40 degrees,
    where the yield drops to nearly zero.
  * The fits fail when the ROOT linear algebra package encounters a
    singular matrix
  * Two solutions were tried
     1. Multiply all matrix elements by 10,000 before testing the
        determinant, rescale results back down as appropriate.
     2. Use tolerance tuning: change the tolerance ROOT uses to call a
        determinant "zero". This tolerance is user settable.
  * Both methods recover much of the deficit, with tolerance tuning
    showing better results.
  * The fix has been put in a branch (kinFitter_debug) of halld_recon so
    other can try it.

 From the discussion:

  * Mark worried that the input covariance matrix for the measured
    kinematic quantities may have errors. that lead to this problem.
    Fixes that give fit convergence may mask a deeper problem.
  * Reinhard has done some research on the subject. Other experiments
    have encountered similar problems. Even if there are problems with
    the covariance matrix formation, the proposed fixes should remain in
    place. They give us a more robust approach to kinematic fitting in
    general.
  * Reinhard also pointed out that having others try out the fix would
    answer concerns about the effect on execution time and precision of
    results.
  * Justin suggested trying the branch in the context of an analysis
    launch as a test.

      CCDB versions and SQLite file management

Mark led a discussion prompted by a incident where the CCDB had errors 
in one of its calibration sets (a translation table). From the agenda:

  * Communication: folks should write to the Software Help List
    <https://groups.google.com/forum/#%21forum/gluex-software> when
    things are broken so others can avoid problems.
  * Finding CCDB SQLite backups: to make it easier to find the backup
    versions we could create links like "ccdb_current",
    "ccdb_yesterday", and/or "ccdb_last-week".
  * Move backups to a more obvious place: We could move the backup
    version into the same directory as the latest version, i. e.
    /group/halld/halldweb/www/html/dist
    <https://halldweb.jlab.org/dist/>, which is web-accessible.
      o We could reorganize that directory. There is a lot of
        heterogeneous stuff there. Any re-org would break old webpage
        links and scripts however.

There was actually not a lot of discussion to lead. People with strong 
feelings should contact Mark.

      Review of Offline Work Packages

Mark update the list of packages based on discussion from the last 
meeting. We took a look at revised list 
<https://halldweb.jlab.org/wiki-private/index.php/2018_Work_Packages>. 
Items now appear in two lists: "Analysis Software" and "Software 
Infrastructure". Only the assignment of volunteers remains to be done.

      Review of recent issues and pull requests

        halld_recon

  * Issue #40: Sean broke the tracking again...
    <https://github.com/JeffersonLab/halld_recon/issues/40> Problem seen
    with ρ yield. Sean is looking at it.
  * Issue #30: Trigger monitoring
    <https://github.com/JeffersonLab/halld_recon/issues/30> Sean has
    ideas to help identify LED triggers that get flagged as physics.
  * Pull Request #43: fix NAN in return value of walk correction code.
    Make sure that square root take a positive value larger than zero
    <https://github.com/JeffersonLab/halld_recon/pull/43> Beni
    eliminated problem when the ADC amplitude is non-positive.

        halld_sim

  * Issue #16: mcsmear crash
    <https://github.com/JeffersonLab/halld_sim/issues/16> There is a
    problem when RCDB cannot find a file for two runs from Fall 2016.
    Sean filed this as an RCDB issue.

      Review of recent discussion on the GlueX Software Help List

We went over the list 
<https://groups.google.com/forum/#%21forum/gluex-software>. No 
discussion of note.

Retrieved from 
"https://halldweb.jlab.org/wiki/index.php?title=GlueX_Offline_Meeting,_October_30,_2018&oldid=89946"

  * This page was last modified on 2 November 2018, at 17:14.

-- 
Mark Ito, marki at jlab.org, (757)269-5295

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