Herwig7 2 2 settings update 10 6

[Dominic-Stafford]

PR description:

Update the Herwig settings blocks so these work with the current version of Herwig. Also update the Powheg+Herwig test to use these blocks, and add tests/examples for Madgraph+Herwig with both mlm and FxFx merging. Will add documentation on how to use these on the Herwig interface twiki: https://twiki.cern.ch/twiki/bin/viewauth/CMS/Herwig7Interface

PR validation:

Checked that all three examples work (Powheg example is runTheMatrix workflow 535)

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

Backport of #33227 for use in UL production

[cmsbuild]

A new Pull Request was created by @Dominic-Stafford for CMSSW_10_6_X.

It involves the following packages:

Configuration/Generator
GeneratorInterface/Herwig7Interface

@SiewYan, @mkirsano, @cmsbuild, @GurpreetSinghChahal, @agrohsje, @alberto-sanchez can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @alberto-sanchez, @mkirsano, @fabiocos this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

• Backported from Herwig7 2 2 settings update #33227

[SiewYan]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-eb52d5/13634/summary.html
COMMIT: b26f204
CMSSW: CMSSW_10_6_X_2021-03-19-1100/slc7_amd64_gcc700
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/33228/13634/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: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 35
• DQMHistoTests: Total histograms compared: 3215541
• DQMHistoTests: Total failures: 2
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3215205
• DQMHistoTests: Total skipped: 334
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 34 files compared)
• Checked 143 log files, 29 edm output root files, 35 DQM output files
• TriggerResults: no differences found

[qliphy]

ping @cms-sw/generators-l2

[SiewYan]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_10_6_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_11_3_X is complete. This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[silviodonato]

Backport of #33227

[qliphy]

+1