[Halld-offline] Minutes of the May 18 GlueX Offline Meeting

Wed May 19 09:27:02 EDT 2010

Find the minutes below and posted at 
http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX_Offline_Meeting%2C_May_18%2C_2010#Minutes

GlueX Offline Meeting, May 18, 2010
Minutes

    JLab: Craig Bookwalter, Mark Ito (chair), David Lawrence, Sascha Somov,
    Simon Taylor, Elliott Wolin, Beni Zihlmann

Announcements

     1. New release: Mark put together a new release,
        [36]sim-recon-2010-05-17, announced yesterday.
     2. Contact with Dmitri: David and Mark have been in email contact with
        Dmitri Romanov about prospective work on a calibration database.
     3. Writing out tracking results: David let us through his recently
        published [37]HOWTO save tracking results to an HDDM or EVIO file
        for later playback.
           + David agreed to give us a tutorial on the use of plugins in
             the JANA framework at a future meeting.
     4. CNU Student: Elliott told us that we will likely get another CNU
        student to work on software this summer via Yelena Prok. He and
        David are discussing appropriate projects, but ROOTSpy is a strong
        candidate.
     5. HDF5: Elliott informed us that Gagik Gavalian, working in Hall B, is
        interested in using [38]HDF5 as a data format for archiving
        analysis results (including calibration constants). Craig has had
        some experience with it, using it for a home-brew ntuple format.


Review of minutes from the last meeting

    We went over the minutes from the May 4th meeting.
      * Mark reported that the Offline Computing change request has been
        entered in the official project software.
      * Elliott reported that Mantis on the way; just a few more details to
        iron out.


Review of the Collaboration Meeting

      * Craig commented that he really appreciated having the graduate
        student workshop at the meeting. Things were learned. Others
        concurred.
      * Sasha asked about what the next steps on the calorimeter cluster
        issues are going to be. David reminded him that a student at IU
        will be working on it. Matt Shepherd has suggested starting him on
        the migration of BCAL smearing to mcsmear as an initial project.
      * Elliott remarked that [41]OpenMP, mentioned in Chip Watson's talk,
        was a simple way to achieve parallelization.


GlueX Software Workshop

    David described the idea, proposed by Paul Eugenio, that we try to have
    a Software Workshop using JSA Initiative funds, along the lines of the
    the [43]CLAS12 workshop scheduled for later this month. The proposal is
    due rather soon (in a month or two). We appointed a sub-committee to
    come up with a proposal for the next offline meeting, after the CLAS12
    workshop occurs. Members are David, Beni, Simon, and Sascha.

JLab Scientific Computing Plan

    Graham Heyes's recently posted [45]plan for the current fiscal year
    generated a lot of [46]discussion on the offline email list. We
    discussed the plan and the discussion.
      * We thought that Chip's characterization of data volume at less than
        1% of an LHC experiment was probably off the mark, low.
      * Graham did not mention JANA in his report in the section on
        reconstruction tools. This will be remedied.
      * Mark asked whether we should revisit our computing plan for GlueX
        as described in the [47]Hall D Design Report, reviewing the
        computing model for the experiment. This was thought to be a good
        idea. This would go a long way to developing a set of requirements.
      * Any requirements should certainly include the SRM or equivalent.
      * Since offsite computing resources are significant in our current
        inventory, and will likely remain so, we should develop an
        infrastructure-appropriate plan to exploit them. Craig pointed out
        that even now, with his CLAS 6 GeV analysis, he is using the FSU
        farm. Blake Leverington has used the UConn OSG site for his GlueX
        thesis work. Sascha mentioned that although the bulk of the
        reconstruction for Belle was done at KEK, outside institutions
        contributed cycles to Monte Carlo generation.


Setting up the GlueX software environment

    Mark led us through his [49]HOWTO set up the GlueX environment wiki
    page. The philosophy is to provide a set of override-able defaults for
    a minimal set of fundamental variables, and then derive all environment
    variables needed to build and run our software from this set.

    David objected to this scheme. No consensus was reached on
    recommendations to the collaboration.

[51]Progress toward constructing our own matrix classes

    Simon presented [52]recent work on a set of custom matrix classes with
    fixed dimensions appropriate to the tracking problem. Improvements come
    from eliminating checking of array dimensions, unrolling loops
    (calculating matrix elements directly), and use if SIMD instructions.
    He achieves increases of speeds of factors of a few for many of the
    operations he benchmarked.

    The next step is incorporate use of these classes in the Kalman filter
    fitter.

Hardware/Connection tracking database

    Beni presented a PHP script he had developed to track components and
    connections for the FDC. It provides an web-based interface for
    entering information as components are produced and wired up. He
    received many comments from the group.

Action Item Review

    We did not get to this. Mark will send out an email to the offline
    email list with a list of outstanding items.

New Action Items

     1. Develop a computing plan for GlueX. -> Mark
     2. Send out list of outstanding action items. -> Mark

    Retrieved from
 
"http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX_Offline_Meeting%2C_May_18%2C_2010"

References

   36. https://halldsvn.jlab.org/repos/tags/sim-recon-2010-05-17/RELEASE
   37. 
http://www.jlab.org/Hall-D/software/wiki/index.php/HOWTO_save_tracking_results_to_an_HDDM_or_EVIO_file_for_later_playback
   38. http://www.hdfgroup.org/HDF5/
   41. http://openmp.org/wp/
   43. http://conferences.jlab.org/CLAS12Software/
   45. 
http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1530
   46. https://mailman.jlab.org/pipermail/halld-offline/2010-May/thread.html
   47. 
http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=58
   49. 
http://www.jlab.org/Hall-D/software/wiki/index.php/HOWTO_set_up_the_GlueX_environment
   51. 
http://www.jlab.org/Hall-D/software/wiki/index.php/Progress_toward_constructing_our_own_matrix_classes
   52. 
http://www.jlab.org/Hall-D/software/wiki/index.php/Progress_toward_constructing_our_own_matrix_classes