Protect against negative occupancy thresholds

[mbandrews]

Modify quality threshold for cases where we see vanishing occupancy:

• Originally: if Entries in a FED < overall FED mean - 5*overall FED rms => set Occupancy Quality to RED
• However, if occupancy is exactly zero, the rms tends to be quite large and the overall FED mean < 5*overall FED rms, so the threshold occupancy < 0. This was seen, for instance, in collisions run 275766, where the Emulation Quality continued to show YELLOW
• To protect against these cases (without tightening the 5 sigma constraint), if threshold occupancy < 0, set threshold occupancy to 10.

In conjunction with 80X PR #14978.

[cmsbuild]

A new Pull Request was created by @mbandrews (Michael Andrews) for CMSSW_8_1_X.

It involves the following packages:

DQM/EcalMonitorClient

@cmsbuild, @dmitrijus, @vanbesien, @davidlange6 can you please review it and eventually sign? Thanks.
@argiro this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[dmitrijus]

+1

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/13684/console

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs after it passes the integration tests. This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar

[cmsbuild]

+1
Tested at: 088eba8
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14979/13684/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14979/13684/summary.html

[davidlange6]

+1