DAQ fix spurious luminosityBlockAuxiliary assertion in HLT (12_0_X)

[smorovic]

PR description:

Fix a crash caused by the missing luminosityBlockAuxiliary object, seen in rare instances at the start of run in production DAQ/HLT.

A race can happen because the local file lock is unlocked before lsToStart is determined.
Since this check involves stat calls for marker files locally, another competing process can in parallel create
the EoL marker file being checked (and cause lsToStart to be increased
above LS of the newly opened file).

In case lsToStart is larger than ls, source would skip opening a lumisection
before ending up processing events and this results in the lumi block
related assertion.

PR validation:

Tested in DAQ filterfarm test system (Openstack VMs). A special test mode was constructed to emulate conditions of crash and find a fix.

if this PR is a backport please specify the original PR and why you need to backport that PR:

Backport of: #35682

[cmsbuild]

A new Pull Request was created by @smorovic (Srecko Morovic) for CMSSW_12_0_X.

It involves the following packages:

• EventFilter/Utilities (daq, reconstruction)

@jpata, @cmsbuild, @emeschi, @smorovic, @slava77 can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @missirol this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

• Backported from DAQ fix spurious luminosityBlockAuxiliary assertion in HLT (12_1_X) #35682

[smorovic]

@cmsbuild please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-940ba5/19646/summary.html
COMMIT: 60bebb8
CMSSW: CMSSW_12_0_X_2021-10-14-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/35683/19646/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 39
• DQMHistoTests: Total histograms compared: 2998564
• DQMHistoTests: Total failures: 0
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2998542
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 38 files compared)
• Checked 165 log files, 37 edm output root files, 39 DQM output files
• TriggerResults: no differences found

[perrotta]

backport of #35682

[smorovic]

+1

[slava77]

+reconstruction

for #35683 60bebb8

• code changes are the same as in the 12_1_X PR DAQ fix spurious luminosityBlockAuxiliary assertion in HLT (12_1_X) #35682; there is no impact on reco

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_12_0_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_12_1_X is complete. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[perrotta]

+1

• Identical implementation of the fix as in DAQ fix spurious luminosityBlockAuxiliary assertion in HLT (12_1_X) #35682, succesfully merged in master since CMSSW_12_1_X_2021-10-15-2300