EDM4hep Discussion
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EDM4hep Live Notes
==================
Date: September 29, 2020
Indico: https://indico.cern.ch/event/960190/
This is a document for taking notes during EDM4hep meetings.
Connected: Weidong, Jiaheng, Wenxing, Tao, Andre, Clement, Frank, Sang Hyun, Thomas, Valentin, Placido
Apologies: Benedikt, Gerri
## Introduction and General Points
## Progress and Discussion
### Spack installation
* Updated CVMFS installation:
* /cvmfs/sw.hsf.org/key4hep/setup.sh
* Also used for fcc tutorial
* Can this repository be part of the defaults?
* bundle package: use "rolling release model" and tag by date, or pin versions
* Added more python packages to key4hep-stack
* Spack as a developer tool:
* PR:
### Nightly Builds and CI
* Entire build CI set up by Joseph
* docker image: key4hep-container on dockerhub
* http://dev1.bitquant.com.hk:8011/
* add tests?
## Podio
### PRs
* https://github.com/AIDASoft/podio/pulls
* Fixes for python and root 6.22, update CI:
* https://github.com/AIDASoft/podio/pull/141
* Merged
* Fix meta data handling
* https://github.com/AIDASoft/podio/pull/133
* Should go before the SIO PR, this PR refactors the tests
#### Merged
* Fix a possible nullptr access in the Writers
* https://github.com/AIDASoft/podio/pull/128
* Make internal maps non-mutable
* https://github.com/AIDASoft/podio/pull/127
* Remove python unittests from installed files
* https://github.com/AIDASoft/podio/pull/126
* Make CollectionIDTable use a std::mutex
* https://github.com/AIDASoft/podio/pull/125
### Using SIO as backend
* Frank and Thomas looking into it
* https://github.com/AIDASoft/podio/pull/130
* IO and tests working
* Small differences in behaviour of ROOTReader/Writer and SIOReader/Writer
* Split test datamodel into small libraries separating SIO/ROOT/Datamodel?
* How to load podioSioIO on demand?
* standalone GaudiPluginManager
* https://github.com/hegner/PM4hep
* Add option to make RootIO optional on build/cmake time
* Cmake: better isolation, reduce number of IFs
* CMake functions to created libraries for different backends
* Exercised with EDM4hep, make a PR with the changes
* podio is backward compatible
### issue w/ ROOT and (vectors of) non-copyable collections
* happens in ROOT 6.22
* PM: there is a patch available in LCG repository
* ROOT team is working on a general solution
### "event class" in podio
* Currently being perceived
### SOLVED: Non-const getter for collection
* original problem (in delphes plugin) has been worked around
* discussion about need for non-const access to collections still ongoing
* little bit related to "event class"
* use case "event overlay"
* alternatively copy everything into new collection
### Multi-Threading
* More than one event "in flight" should be possible
* TM: root reader seems to be capable, root writer maybe not
* FG: easier to handle with "event class"
*
### Meta Data
#### Usage of "metadata" for user defined data
* need to check if current implementation addresses all use cases
* need test use-cases
### Issues following MetaData Developments
* cannot write out event data previously read from file
* Issue: https://github.com/AIDASoft/podio/issues/103
* Test: https://github.com/AIDASoft/podio/pull/102
* TM: have fix, but break framework core handling of collections
* there seems to be a fix in the Gaudi ROOTWriter in FCC-EDM !?
* historical reason, fixes and developments should be back ported to PODIO
* ...
#### Writing second file with another tree
* https://github.com/key4hep/K4FWCore/issues/10
* this problem only happens in the GAUDI framework
* if user tries to write an additional ROOT file
* to be addressed
### EventStore
### Schema Evolution
- Version for object descriptions, etc.
- Open issue: https://github.com/AIDASoft/podio/issues/86
### Features
* Subset collections?
## LCIOConverters
* Conversion from LCIO to EDM4HEP is almost completed, but we need more testing for the three associations:
* MCRecoParticleAssociation
* MCRecoCaloAssociation
* MCRecoTrackerAssociation
* LCIOInput, an algorithm wrapper in Gaudi/K4FWCore
* https://github.com/ihep-sft-group/LCIOInput
* K4LCIOReader:
* https://github.com/ihep-sft-group/K4LCIOReader
* Used to reconstruct clusters with Pandora
* Publish Pandora Interface on github
* working on spack recipe for CEPC software
* will report in next meeting
## EDM4hep
https://github.com/key4hep/EDM4hep/pulls
### Tracker Hit
* Q: Tracker hit input to tracking algorithms?
* A: In LCIO different traker hits: Planar and Cylindrical using inheritance. Still needs to be adressed how to do this in EDM4hep.
* Q: Is inheritance needed?
* Q: What to use for Driftchambers?
* Open issue:
### PRs
* Fix delphes EDM4Hep plugin
* https://github.com/key4hep/EDM4hep/pull/79
* Problem with the CI
* podio taken from the wrong place at Runtime?
* Need to set LD_LIBRARY_PATH to point to new podio
* Ready for review
* Add a mention of the example to the key4hep docs:
* https://github.com/key4hep/key4hep-doc
### Release 1.0
* Need:
* ~~Plugin~~
* ~~Eventheader~~
* ~~Meta Data (Event / Run Parameters)~~
## AOB
### Relevant Meetings
* Multi-Threaded Metadata Handling: Athena
* https://indico.cern.ch/event/958266/
* Wednesday September 30 16:00
* An Introduction to Modern CMake (HSF Software Developer Tools & Packaging Working Group)
* https://indico.cern.ch/event/956862/
* Wednesday September 30 17:00
### Update on postdoctoral grant from Hong Kong Innovation Technology Fund for HEP software development
* Possibility for founding of up-to 4 people
* Grad students, post-docs
* Discussing with Graeme/HSF
* RnD for data analysis tools and system integration to study electro-weak meta stability
* Looking for high performance components for data analysis
### Dual Read-out calorimeter for FCC
* Special data structure used for that simulation
* Tried to use edm4hep, some issues
* Present in a future meeting
### Conditions handling in Belle2
* Benedikt, or Martin Ritter
### Feedback from FCC tutorial for snowmass
* Common question: What are the different branches in the root file?
* ``uproot`` was also used to access the root file
* Basically re-implemented event store
* Associations
* Try to get this into the, e.g., podio repository
### Next meeting:
* October 13, 2020