Build SIM geometry from DB

[civanch]

It is necessary to establish build of SIM geometry from DB without use of DDD components and DB records, which are obsolete. Start of the discussion was in #34167

[cmsbuild]

A new Issue was created by @civanch Vladimir Ivantchenko.

@Dr15Jones, @dpiparo, @silviodonato, @smuzaffar, @makortel, @qliphy can you please review it and eventually sign/assign? Thanks.

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[civanch]

assign geometry

[cmsbuild]

New categories assigned: geometry

@Dr15Jones,@cvuosalo,@civanch,@ianna,@mdhildreth,@makortel you have been requested to review this Pull request/Issue and eventually sign? Thanks

[civanch]

assign core

[cmsbuild]

New categories assigned: core

@Dr15Jones,@smuzaffar,@makortel you have been requested to review this Pull request/Issue and eventually sign? Thanks

[makortel]

@cvuosalo, replying here to #34167 (comment). Thanks for trying out. After further thought I think the following would be (also conceptually) a better version of #34167 (comment)

                    if self.geometryDBLabel:
                        self.executeAndRemember('if hasattr(process, "XMLFromDBSource): process.XMLFromDBSource.label="%s"'%(self.geometryDBLabel))
                        self.executeAndRemember('if hasattr(process, "DDDetectorESProducerFromDB"): process.DDDetectorESProducerFromDB.label="%s"'%(self.geometryDBLabel))

[cvuosalo]

@makortel Thanks, your new version works, at least so far. There is more to be fixed (see next comment).

[cvuosalo]

Request for advice: It looks to me like Configuration/Geometry/python/GeometryDB_cff.py needs to be changed to include DDD and DD4hep options. Currently, it contains:

from Configuration.Geometry.GeometryRecoDB_cff import *
from Configuration.Geometry.GeometrySimDB_cff import *

Those cff files currently contain DDD-specific code.

I think GeometryDB_cff.py should contain a DDD section and a DD4hep section. In pseudo-code, it might look something like this:

from Configuration.ProcessModifiers.dd4hep_cff import dd4hep

# DDD only
from Configuration.Geometry.GeometryRecoDB_cff import *
from Configuration.Geometry.GeometrySimDB_cff import *
# DD4hep only
from Configuration.Geometry.GeometryRecoDBDD4hep_cff import *
from Configuration.Geometry.GeometrySimDBDD4hep_cff import *

I think that the dd4hep.toReplaceWith syntax could be used to make this choice. Is GeometryDB_cff.py the right location to branch between DDD and DD4hep configs?

[makortel]

The dd4hep.toReplaceWith() should be used for cases where the meaning of a module label is re-defined with another module of the same type (e.g. replace ESProducer with a different ESProducer). The replacement should be done in the (cfi) file that defines the module.

Different sets of cfi/cff files can be loaded into the Process along what I described in #34167 (comment). Even then I'd recommend to load as small configuration fragments at a time as possible (e.g. I'm a bit concerned that full GeometryRecoDB_cff could be too complex). In the end it really depends how many module labels are the same between DDD and DD4Hep setups, and how many are different (as in #34167 (comment)).

[cvuosalo]

@makortel Here's what I am trying in GeometrySimDB_cff.py (and similarly in GeometryRecoDB_cff.py):

from Configuration.ProcessModifiers.dd4hep_cff import dd4hep

def _loadGeometryDBDDD(process) :
    process.load('Configuration.Geometry.GeometryDDDSimDB_cff')

def _loadGeometryDBDD4hep(process) :
    process.load('Configuration.Geometry.GeometryDD4hepSimDB_cff')

modifyGeometryConfiguration = (~dd4hep).makeProcessModifier(_loadGeometryDBDDD)
modifyGeometryConfiguration_dd4hep = dd4hep.makeProcessModifier(_loadGeometryDBDD4hep)

The cff files that are loaded are about 20 lines long. Is that too complex?

[cvuosalo]

Draft PR #34219 submitted for discussion.

[cvuosalo]

I have created a possible config for DD4hep sim from the DB. However, it fails with this exception:

Running EventSetup component DDCompactViewESProducer/'
Exception Message:
No data of type "DDDetector" with label "" in record "IdealGeometryRecord"
 Please add an ESSource or ESProducer to your job which can deliver this data.

It is puzzling, because the configs do contain the needed producers (below). What is missing?

process.DDCompactViewESProducer = cms.ESProducer("DDCompactViewESProducer",
    appendToDataLabel = cms.string('')
)
process.DDDetectorESProducerFromDB = cms.ESSource("DDDetectorESProducer",
    appendToDataLabel = cms.string(''),
    fromDB = cms.bool(True),
    label = cms.string('Extended'),
    rootDDName = cms.string('cms:OCMS')
)

[cvuosalo]

This issue has been resolved. DD4hep workflow 11634.912 reads DD4hep geometry from the DB.

[cvuosalo]

+1

[tvami]

@cms-sw/core-l2 please sign this issue, since it's been resolved. Thanks!

[makortel]

+core

[cmsbuild]

This issue is fully signed and ready to be closed.