[Halld-offline] Minutes, GlueX Offline Meeting, Jan. 12 '11

[Mark M. Ito]

Find the minutes at 
http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX_Offline_Meeting%2C_January_12%2C_2011#Minutes 
and below.

==

GlueX Offline Meeting, January 12, 2011
Minutes

Present:
* FSU: Nathan Sparks
* IU: Jake Bennett, Ryan Mitchell, Kei Moriya, Matt Shepherd
* JLab: Hovanes Egiyan, Graham Heyes, Mark Ito (chair), David
Lawrence, Yi Qiang, Dmitry Romanov, Simon Taylor, Beni Zihlmann


Announcements

Mark encouraged people to start thinking about what talks they want to
give at the [36]upcoming Collaboration Meeting in the Offline session.

Parallelism Workshop

David gave some impressions from last week's [38]Workshop on
Parallelism in Experimental Nuclear Physics. Fifty five people
registered and a like number attended. There were lots of interesting
and informative talks, featured among them talks from folks outside the
JLab community. See [39]David's email for his summary for the
participants and a link to the virtual machine that has the hands-on
examples loaded on it.

In discussion Matt asked if JLab has licenses for [40]Purify. Graham
said that it did; he would look into who owns it now.

Review of IT Readiness for the 12 GeV Era

Graham described the upcoming review of all computing plans for 12 GeV
era. The review will be comprehensive in that it will include
accelerator controls, data acquisition support software, the Computer
and Network Infrastructure Department (CNI) and the Management
Information Systems Department (MIS). Some of his points:
* want to determine if we can handle data coming from experiments
* need an outline of remarks by all speakers by end of month
* the review will be around the 2nd week of March
* Graham will send around a spreadsheet, asking for updates to
computing requirements from various groups
* scheduled speakers: Bob Michaels from Hall A, Dennis Weygand from
Hall B, Mark Ito from Hall D, a representative from Hall C--TBA,
and Graham with an overview
* current computing requirements:
+ Hall D: compute intensive
+ Hall B: storage intensive
* storage more of a worry
* this will be an internal (to JLab) review
* a pre-cursor to external review in a year or so


Changes to TOF Code

Beni described recent changes he has made to the HDDM data model to
accommodate information from the Monte Carlo about "truth" information
related to time-of-flight hits. In some cases, new elements were
introduced to be able to keep both generated and detected information,
and some elements were expanded to store information about the particle
producing the hits.

A lot of discussion followed on the general idea of keeping generated
quantities ("truth") and detected quantities ("hits") separate in our
analysis. Some of Beni's changes seemed to violate this separation.
Beni, Mark, and David agreed to meet after the meeting to discuss
alternate approaches that preserve the information desired, but make
the above mentioned separation more explicit.

Tracking Issues

Kei presented a list of bugs/anomalies that he has come across in
running our reconstruction code. See [44]his talk for details. He
mentioned four items:

0. event processing hangs every ~1000 events for his event topology
1. pi+ events reconstructed as proton show “spike” in momentum at ~0.5
GeV/c
2. some events have direction of momentum “reversed”
3. values of variables are set to non-physical values when they cannot
be defined for a given track (leads to side-effects if not checked for
explicity)

Work continues to try to resolve these mysteries.

Side note: Mark encouraged folks to write to halld-offline at jlab.org
when they encounter problems like this so that (a) we all are aware of
the problem (b) others that encounter similar problems can benefit from
the conversation.

Action Item Review

We looked over recently resolved items and those outstanding. David has
added some items based on feedback from the workshop. Mark got David to
volunteer to update the Build Make System (BMS) document to bring it
up-to-date.

New Action Items

1. Look into the Purify license. -> Graham
2. Send email to the list on recent problems in the offline code. ->
Kei
3. Prepare revised computing requirements for IT review. -> Mark
4. Revise BMS document. -> David
__________________________________________________________________

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References

36. 
http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX-Collaboration-Jan-2011
38. http://conferences.jlab.org/Parallelism2011/
39. 
https://halldweb1.jlab.org/talks/2011-1Q/Parallelism%202011%20Workshop%20Talks%20available.txt
40. http://en.wikipedia.org/wiki/IBM_Rational_Purify
44. 
https://halldweb1.jlab.org/talks/2011-1Q/offline-software.Kei-Moriya.2011-01-12.pdf