sPHENIX discussion of software

[pinkenburg <pinkenburg AT bnl.gov>]

Hi Dmitri,

these properties are kept in a map and only created if they are actually 
filled in the stepping action (e.g. path_length for a hit in a 
calorimeter shower is pointless). If you access a property which does 
not exist it returns the default. In 
coresoftware/simulation/g4simulation/g4main/PHG4Hitv1.cc the 
PHG4Hitv1::print() const method has a loop which extracts only existing 
variables.

These property maps while convenient to work with sadly are likely a 
large contributor to roots memory consumption. If there is an idea how 
to stream this in a way which is more root friendly - I'd love to hear 
more about it.

I think this came up recently - Jan Bernauer worked out an example 
replacing root i/o by flat buffers:
https://google.github.io/flatbuffers/
If we can pull this off I would hope that this will reduce our memory 
problems significantly.

Chris


On 12/4/2020 6:59 PM, Dmitri Smirnov wrote:
> Not sure if it is a know issue but I noticed that some properties of 
> PHG4Hit are not filled in files from 
> /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/G4Hits/data
> For example, path_length, layer, row, and hit_type are filled with 
> default values.
>
>
> On 11/30/20 6:31 PM, pinkenburg wrote:
> > Hi folks,
> >
> > The Geant4 processing has been ongoing and we have close to 500,000 
> > events from the initial geant4 processing. The reconstruction chain 
> > needs some work but is basically functional up to jets. I split it 
> > into six separate steps 
> > (https://github.com/sPHENIX-Collaboration/MDC1/tree/main/submit):
> >
> > pass1:
> > Geant4 simulation of sHijing, output (G4Hits of all active detectors) 
> > is written to
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/G4Hits/data
> > Each file contains 100 events
> >
> > pass2:
> > 50kHz pileup generation, output is split into 4 files
> > DST_BBC_G4HIT_sHijing_0_12fm contains bbc and epd G4Hits
> > DST_CALO_G4HIT_sHijing_0_12fm contains all calorimeter G4Hits
> > DST_TRKR_G4HIT_sHijing_0_12fm contains tracking detector G4Hits
> > DST_TRUTH_G4HIT_sHijing_0_12fm contains the truth info (and HepMC 
> > records and black hole hits)
> > the output is written to:
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/PileUp/data
> > Each file contains about 50 events.
> >
> >
> > pass3calo
> > processing of calorimeter data from the DST_CALO_GHITS files, towers 
> > (all flavors) and clusters are saved. I tried the topo clusters but 
> > it ran out of memory (I killed it as it reached 40GB).
> > the output is written to
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/CaloCluster/data
> >
> >  pass3trk:
> > tracking pre-pass: tpc electron drift and clustering, silicon g4hit 
> > clustering and silicon seeds from truth info using DST_TRKR_G4HIT and 
> > DST_TRKR_G4HIT files. Saves clusters for the tracking
> > the output is written to
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/TrkrCluster/data
> >
> > pass4trk:
> > tracking and vertex reconstruction with ACTS (also rave vertex)
> > the output goes to
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/Tracks/data
> >
> > pass5jet:
> > jet reconstruction based on tracks (clusters need a vertex)
> > the output goes to
> > /sphenix/data/data02/sphnxpro/MDC1/sHijing_HepMC/Jets/data
> >
> >
> > all files contain the data needed for the synchronization so one can 
> > mix and match whatever is needed. There is a decent amount of 
> > calorimeter files, tracking (and jets) are single files used to 
> > establish that this works. But they can certainly be used to check if 
> > they work as input for analysis.
> >
> > Chris
> >
> >
> > *************************************************************
> >
> > Christopher H. Pinkenburg    ;    pinkenburg AT bnl.gov
> >                 ;    http://www.phenix.bnl.gov/~pinkenbu
> >
> > Brookhaven National Laboratory    ;    phone: (631) 344-5692
> > Physics Department Bldg 510 C    ;    fax:   (631) 344-3253
> > Upton, NY 11973-5000
> >
> > *************************************************************
> >
> > _______________________________________________
> > sPHENIX-software-l mailing list
> > sPHENIX-software-l AT lists.bnl.gov
> > https://lists.bnl.gov/mailman/listinfo/sphenix-software-l

--
*************************************************************

Christopher H. Pinkenburg       ;    pinkenburg AT bnl.gov
                                ;    http://www.phenix.bnl.gov/~pinkenbu

Brookhaven National Laboratory  ;    phone: (631) 344-5692
Physics Department Bldg 510 C   ;    fax:   (631) 344-3253
Upton, NY 11973-5000

*************************************************************