GlueX Offline Meeting, February 5, 2014

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GlueX Offline Software Meeting
Wednesday, February 5, 2014
1:30 pm EST
JLab: CEBAF Center F326/327


  1. Announcements
  2. Tagged File System for Event Data (Gagik Gavalian)
  3. Review of minutes from the last meeting: all
  4. Collaboration Meeting Agenda, February 20-22
  5. Data Challenge Meeting Report, January 31
  6. Reverse Magnetic Field Fix (Simon)
  7. TOF Geometry Change (Beni)
  8. Mantis Bug Tracker Review
  9. Review of recent repository activity: all

Communication Information

Video Conferencing

Desktop Sharing

You can view the computer desktop in the meeting room at JLab via the web.

  1. Go to
  2. In the "join a meeting" box enter the Hall D code: 1833622
  3. Fill in the participant registration form.


To connect by telephone:

  1. dial:
  2. enter access code followed by the # sign: 1833622#


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2014-1Q on the JLab CUE. This directory is accessible from the web at .



  • CMU: Will Levine, Paul Mattione, Curtis Meyer
  • FSU: Aristeidis Tsaris
  • IU: Kei Moriya
  • JLab: Mark Dalton, Gagik Gavalian, Mark Ito (chair), David Lawrence, Dmitry Romanov, Simon Taylor, Beni Zihlmann
  • MIT: Justin Stevens
  • NWU: Sean Dobbs

Find a video of the meeting here.


  • We will have a data challenge meeting Friday, February 7 at 11:00 am.

Tagged File System for Event Data

Gagik presented his system for distribution of event data for the data mining project at ODU. See his slides for details. He addressed:

  • Data Storage and Compression
  • Data Format
  • Data Distribution and Discovery
  • Tag-Filesystem Associated Tags
  • Tag-Filesystem Distributed System
  • Ideas (GlueX-related)

The system is designed to retrieve a user-defined data set onto a local storage. There are two levels of selection: tags and filters. Tags identify specific sets of data files. Each file can be tagged in different ways and the tags may describe an arbitrary set of properties of the data, for example beam energy tags and and target type tags. Filters are routines that select individual events from each data file and are applied at request-fulfillment time. An example is event topology, e. g., the number of charged particles. The storage and retrieval system can be distributed over several servers and thus should scale.

We ran out of time for everyone's questions to be answered. A follow-up session with Gagik will be arranged.

Collaboration Meeting Agenda

Mark will ask Richard if he would like to talk about Geant4 conversion and related geometry changes.

Data Challenge Meeting Report

We looked over the minutes from the January 31 meeting. We deferred discussion of these items until the next meeting on February 7.

Reverse Magnetic Field Fix

Simon reported on the fix he checked in. Both HDGeant and the reconstruction get their magnetic field via the resource mechanism of JANA. In particular they now use the new 1350 A field with a polarity reverse of what we have been using up until now. There were several small changes that had to made to the tracking code to accommodate this change.

There is still a glitch in the acceptance at phi = 0 that seems a remaining corner of the backward-angle-CDC-stereo-straw problem that was largely fixed by Richard. Beni has confirmed the problem in a study where the straws were turned to lead and geantinos used to illuminate the CDC. Simon has sent Richard some plots documenting the problem.

Time-of-Flight Geometry Change

Beni has updated the TOF geometry to reflect the half-width counters we have near the beamline. There were corresponding changes necessary in the simulation and reconstruction. These have all been checked in.

There was some discussion about whether the internal numbering scheme for the counters was natural and consistent. No conclusions were arrived at about whether this even matters. Further discussion will follow in a smaller group.

Single-Track Test and JANA Versions

  • The single-track test failed on the most recent attempt. The test is now using CCDB 0.09 and JANA 0.7.1.
  • JANA 0.7.p1 has been released. It fixes a few minor issues:
    • Default directory choosing, when unspecified by the user, for storing resources had a bug.
    • The make-plugin script now uses scons in favor of make.

Code Validation

Curtis asked about this issue.

  • Mark has a cron job that makes an attempt at making a performance benchmark on the code. Such attempts are currently failing.
  • David has worked on the suppression script for filtering sketchy practices flagged by valgrind.
  • This issue needs to be moved up in priority.

Action Items

  • Circulate document on database/webserver deployment developed by JLab IT. -> Mark
  • Research IT Division procedure for restoring a backup of the MySQL database. -> Mark
  • Implement pre-caching of resources. -> Mark, David
  • Ask about event format requirements for EventStore. -> Sean
  • Take the TOF geometry indexing discussion offline. -> Mark
  • Move code validation up in priority. -> Mark