[Halld-offline] Offline Software Meeting Minutes, July 11, 2012

[Mark M. Ito]

Folks,

Find the minutes below and at

https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_July_11,_2012#Minutes

   -- Mark
_____

    GlueX Offline Software Meeting
    Wednesday, July 11, 2012
    1:30 pm EDT
    JLab: CEBAF Center, F326/327

Minutes

    Present:
      * CMU: Will Levine, Paul Mattione, Curtis Meyer
      * IU: Ryan Mitchell, Matt Shepherd
      * JLab: Eugene Chudakov, Mark Ito (chair), David Lawrence, Simon
        Taylor, Elliott Wolin
      * UConn: Richard Jones

Planning for the next Data Challenge

    Curtis introduced the topic and lead us through [22]his GlueX Note. The
    contents
     1. Introduction
     2. Earlier Data Challenges
     3. Goals of The Next Data Challenge
     4. Procedures
          1. Generate pythia Events
          2. Inject Physics into the Sample
          3. Producing DSTs from the Monte Carlo
          4. Physics Analysis of DSTs
          5. Amplitude Analysis of mini-DSTs
     5. Conclusions

    See his notes for details.

    Mark then led us through a set of [23]notes outlining a possible
    direction.
      * Ideas: He summarized communication from interested folks since the
        last offline meeting.
      * Tools: He listed some tools that may help us.
      * Mini Data Challenges: He proposed a series of short data challenges
        to help develop tools and refine goals.
      * Analysis System: He endorsed Matt's idea that we include a
        reconstructed data delivery system as part of this effort.

    See his wiki page for details.

    Discussion:
      * David suggested that we get more than one person involved in the
        effort.
      * Richard advocated the use of [24]glideinWMS as a work management
        system rather than [25]PanDA.
      * David wondered whether the extra layer of a work management system
        gave us any real benefit. Richard pointed out that some of the
        functionality that Mark mentioned (tracking output files, etc.) may
        not be provided by these systems.
      * Curtis announced that he has asked Mark and Matt to manage the
        effort. Bi-weekly meetings will be called.

REST Format

    Richard ran generated some data on the grid with the current analysis
    framework to measure the size of the [26]REST output events. He
    simulated events with 5 pions and a proton in the final state.
    Section Size (bytes) Comment
    Monte Carlo 500 particle list with kinematics, vertices
    Tagger 170 20 hits on average
    Clusters 600 9 on average, notation about track matching
    DChargedTrackHypothesis 1484 9 on average

    Total event size is on average about 2.7 kB, 1.8 kB after compresssion.
    Other comments:
      * Off-diagonal elements of the covariance matrices for the clusters
        are often zero.
      * No kaons are produced at present.
      * Antiprotons are seen in the data.

    Richard then followed a suggestion by Paul and Matt to store more
    information from lower levels in the reconstruction.
      * Rather than recording timing chi-squareds, record actual times of
        TOF hits: adds 70 bytes
      * Similar increase for start counter hits.

    These will be included in the future.

    There was a discussion about whether the lower-level DTrackTimeBased
    should be used rather that DChargedTrackHypothesis. The problem is that
    this object has way more member data than we want to serialize. Matt
    suggested writing out just the relevant member data and protecting
    access of missing data by generating errors in their gettor functions
    when the data is not present. We agreed to follow this approach.

    Richard also looked into using ROOT trees as a DST format. He found a
    fundamental conflict between the way events are accessed from a ROOT
    tree and the JANA multi-threaded architecture when the ROOT tree is
    used as an input file. Creating ROOT trees for subsequent analysis by
    ROOT is not an issue, of course.

New Action Items

     1. Look into track hypotheses that are produced by default. -> Simon
     2. Reconfigure REST to use DTrackTimeBased. -> Richard

    Retrieved from
"https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_July_11,_2012"

References

   22. 
http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2031
   23. https://halldweb1.jlab.org/wiki/index.php/Notes_on_the_Data_Challenge
   24. 
http://www.uscms.org/SoftwareComputing/Grid/WMS/glideinWMS/doc.prd/index.html
   25. https://halldweb1.jlab.org/talks/2012-3Q/ASCR_PanDA_9.1.pdf
   26. https://halldweb1.jlab.org/talks/2012-3Q/rest.xml

-- 
Mark M. Ito
Jefferson Lab (www.jlab.org)
(757)269-5295