LHCb Core Software Meeting

Date and Location

09-May-2012

Attendees

Subjects

News

• CHEP rehearsals starting today (part I, part II, part III, part IV
• Forum on Concurrent Programming Models and Frameworks today
• Architects Forum Meeting tomorrow
• Librarian and Integrators meeting yesterday
  • to check if SLC6 will be available in LCG 63
  • Giulio Eulisse mentioned some problems CMS had with RPM. Further discussion planned.

Round Table

Marco Cl.

• Reported ROOT bug #94227: was causing the failure in Erasmus reported by Thomas last week
  • the fix caused other failures in Erasmus, which have been fixed
• A problem in VeloDDDB has been found after a report on a mailing list. Patched version already released.
• Problem with jobs failing on old versions of ONLINE CondDB partition.
  • the failure was due to the fact that the working directory of the pilot job was used to run a prompt reconstruction (downloading ONLINE) on one day, then it was re-used two days later to run a normal reconstruction (no update), which picked up the old ONLINE snapshot already there.
  • there are 3 possible solutions:
    • require "use SQLDDDB" in every job, but we do not need/want it
    • remove "use SQLDDDB" from every job, but we have problems with the prompt reconstruction
    • purge the local MYSITEROOT between two jobs in the pilot, but it's more complicated
  • once we have the new CVMFS volume for CondDB, we can have a more frequent refresh, so we can get rid of "use SQLDDDB"

Ben

• Problem with a release of Erasmus, because of mkproject did not report the failure.
  • it is not clear why mkproject does not behave, because the code seems correct
• New version of LbScripts, because there are 2 new packages that can be released/installed
  • install_project uses a dynamic list, so it is not a problem to add packages, but other tools use an hard-coded one, and they need to be fixed
• Progress in changing the default CMTCONFIG
  • the default comes from a prioritized list in Platforms.py, but a change there means a change for everybody
  • to test at CERN, we can modify the CERN group login (ugly, but easy)
  • we cannot change yet the default, because Ganga does not work with gcc 4.6
• Investigating the performances of Brunel, discovered a ~5% fluctuation in the CPU time used (CPU ticks), while it should be more deterministic
  • a possible cause of this effect is differences in the access to the memory in different executions (because of cache misses)
  • will investigate further

Gloria

• Discovered (with Marco Cl.) the reason of segfaults in the generation of configurables in GaussRICH
  • service where retrieved in constructors, thus, after the splitting of GaudiSvc, invalidating iterators in genconf
  • GaussRICH has been fixed (to be validated by Sajan). Marco Cl. says he can had a proper error message in genconf, instead of the segfault.
• There are still compilations problems with gcc 4.6

Marco Ca.

• Hard limits on memory on grid sites have been hitting Stripping jobs, see bug #94439.
  • We need to think about possible improvements at the framework level.

-- MarcoClemencic - 09-May-2012