GlueX Offline Meeting, December 7, 2016
GlueX Offline Software Meeting
Wednesday, December 7, 2016
2:00 pm EST
JLab: CEBAF Center F326/327
- 1 Agenda
- 2 Communication Information
- 3 Minutes
- Split of /group and multi-factor authentication (MFA) issues (Paul Letta, CNI)
- Review of minutes from the last meeting (all)
- Report from SciComp Meeting of November 17
- Launches (Paul M./Alex A.)
- Geometry Issues in sim-recon (Sean)
- Review of recent pull requests (all)
- Review of recent discussion on the Gluex Software Help List.
- Action Item Review
- The BlueJeans meeting number is 968 592 007 .
- Join the Meeting via BlueJeans
Talks can be deposited in the directory
/group/halld/www/halldweb/html/talks/2016 on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2016/ .
- CMU: Curtis Meyer
- Glasgow: Peter Pauli
- JLab: Alexander Austregesilo, Thomas Britton, Mark Ito (chair), Nacer Hamdi, Paul Letta, Paul Mattione, Nathan Sparks, Simon Taylor, Beni Zihlmann
- NU: Sean Dobbs
There is a recording of this meeting on the BlueJeans site.
- Mark called our attention to the three releases of sim-recon since the last meeting a month ago:
- Flash 250 Emulation. Sean reminded us about improved fidelity with the firmware and the new reporting of errors from compression.
- mc_generic CCDB variation. Sean pointed the existence of this new variation, intended to help users who don't know or care about the details of the calibration settings for simulated data, for example, those starting to learn the system.
- Sim 1.2 test jobs running. Mark reported that jobs are running under both CentOS65 and CentOS7 for this initial test.
Split of /group and multi-factor authentication (MFA) issues
Paul Letta of CNI gave a presentation describing the changes coming up in the new year. The two major things to look for:
- Split of the group disk directories into sensitive (JSA Data) and non-sensitive (Open Science Data) file systems.
- Requirement of an MFA token to access JSA Data.
One general theme (among others) is that, by and large, Lab Users from collaborating institutions will not be affected by this change. Another is that those working with internal Lab documents for the bulk of their work, for example folks in Procurement, will need the token for most of their work.
Please see his slides for the details and exact definitions.
Review of minutes from the last meeting
We looked over the minutes from November 9. Mark reminded us that the Software Review was held just after that meeting. It went very well for us; the only recommendation was to explore doing data compression in the crates to help with bandwidth.
SciComp Meeting of November 17
Mark flashed his notes from the meeting. Main message: the CentOS7 farm nodes are up and running now.
Alex A. brought us up to date on the on-going Analysis Launch.
- He is using the 40 new CentOS7 nodes, each with 72 threads available. However he is only able to run 18 threads though he is running alone on the node due to memory usage.
- Why so much memory? There are 100 reactions being analyzed, including 40 from Ryan Mitchell's new, comprehensive, final-state-survey plug-in.
- We are now just shy of the 50% point.
- Paul is working on memory reduction in the analysis library. The major culprit are high-multiplicity final states, which generate many kinematic fits, each fit producing a large error matrix that needs to be saved. One thing he is trying is to save the matrices as floats, not doubles.
- It was noted that there are just a few plug-ins responsible for high memory demand.
- Mark wondered if there are photon quality cuts that can be applied to reduce the number of particle combinations tried. The threshold is already at 100 MeV which we would not like to increase, but perhaps there are other parameters to play with.
- Alex estimates that "the first part[?]" will be done in 10 days, with the second part running over the holiday shutdown.
- Alex showed us the Launch webpage. The jobs are running at a steady rate, maintaining 40 instances corresponding the the 40 new nodes.
Geometry Issues in sim-recon
Sean presented ideas he will flesh-out in an upcoming GlueX Note. He addressed the issue of how we handle changes in geometry, either due to reconfiguration (both major and minor), or re-assessments of positions at a fixed point in time (for example development of better alignment procedures). Both of these sources of variations are naturally captured in the CCDB. His proposal is to (a) control the version of HDDS XML files via the CCDB for configuration changes and (b) also control a set of offsets, hopefully small, in the CCDB that capture variation from an ideal geometry. He also presented the structure for serving out geometry information inside JANA. Please see his slides for details.
We had some discussion of how we decide which information goes where: does some particular change in an offset represent a configuration change and thereby requires a new XML file, or simply a run-dependent variation from some nominal setting. We will have to develop a philosophy on deciding these questions at some point.
Event Viewer Plans
Thomas is looking into developing a new event viewer for GlueX. He has been reviewing features of hdview2 as well as looking at adopting the ROOT-based EVE package for rendering a 3D representation of the detector. He has already succeeding in generating pictures with EVE using the existing ROOT geometry generated by the HDDS package. Dmitry Romanov did some work along these lines in the past. Thomas hopes to work with him when his visit starts in February.