EDM4hep Discussion
Zoom
EDM4hep Live Notes
==================
Date: February 23, 2021
Indico: https://indico.cern.ch/event/1010944/
This is a document for taking notes during EDM4hep meetings.
Connected: Weidong, Andre, Jiaheng, Teng, Benedikt, Frank, Sanghyun, Thomas, Clement, Birgit, Placido, Wenxing, Gerri, Tao, Xingtao, Pere,
Apologies: Valentin
## Introduction and General Points
### Virtual Chep
* **First Drafts last week, Tuesday**
* papers(!) due February 28, 2021
* Submissions should consist of a paper of 6-10 pages, following the instructions for authors. Paper submission is open until 28 February 2021.
* https://indico.cern.ch/event/948465/page/21562-instructions-to-submitters
* Contribution:
* Key4hep overview
* https://www.overleaf.com/read/trthzxscrvtp
* Benedikt: What is missing: what are the next steps; How to join the project; where to get more information, how to approach the developers. Couple phrases, intro, conclusion or its own section
* Clement: Minimum requirements for software to be added to Key4hep? Based on k4FWCore or EDM4hep?
* Frank/Benedikt: should stay open, will be a long discussion otherwise
* Authors
* Opt-in, editors check that no-one is forgotten
* Andre will send an email for people to opt-in
* podio+edm4hep!
* https://www.overleaf.com/project/6006bcda6d620e14455b642b
* Submission:
* Final version Thursday night
* Proofreading until Friday afternoon and then submission
* Final editing session Friday 15:00 CET (Key4hep), ~16:00 CET (Podio)
## Progress and Discussion
## Podio
### New tool to draw EDM as defined in yaml
### Benchmarking
[Thomas] Added some scripts and tools to have almost automatic benchmarking and some results using k4SimDelphes to "generate" data for I/O. Could be made fully automatic with a bit more work and if we want it to be fully automatic.
* https://github.com/tmadlener/podio_benchmarking
* Example results: https://github.com/tmadlener/podio_benchmarking/tree/master/results/k4SimDelphes/ee_Z_bbbar
* https://root-forum.cern.ch/t/serious-degradation-of-i-o-performance-from-6-20-04-to-6-22-06/43584
### Issues/PRs
#### Heap-use-after-free
* https://github.com/AIDASoft/podio/issues/174
* Not a problem in frameworks, but if collections used outside of them
* Deep inside the memory management of podio, so not easy to fix
* Happens more often with clang than with gcc, but could be compiler options.
* Flagged by address-sanitizer
* Compare with the DD4hep "Handle"s
* LINK:
#### more fixes to unsigned and shadowed variables
* https://github.com/AIDASoft/podio/issues/170
* https://github.com/AIDASoft/podio/pull/171
* Make a tag after all the warnings are fixed
* sign vs unsigned
* using negative values for some special cases (invalid, untracked), could use largest unsigned, or cast to signed when comparing with vectors
* Maybe better to leave it signed to avoid possible issues with `max<unsigned> - 1`
* Use a typedef for the "podIDType"?
*
#### c++ concepts
* BH: add compile time checks for class behaviours: e.g., movable
#### 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
#### What are the different branches in the root file?
* Related to use in RDataFrame
* Encode more information in the _relation_ branch names?
#### Multi-Threading
See minutes of https://indico.cern.ch/event/969468/
--> Open issue(s) for further discussion
* Thomas and Benedikt discussing and started to work, nothing to report yet
#### "event class" in podio
* Currently being perceived
### PRs
* https://github.com/AIDASoft/podio/pulls
### Meta Data
#### Usage of "metadata" for user defined data
* need to check if current implementation addresses all use cases
* need test use-cases
### EventStore
### Schema Evolution
- Version for object descriptions, etc.
- Open issue: https://github.com/AIDASoft/podio/issues/86
### Features
* Subset collections?
## LCIOConverters
* https://github.com/key4hep/k4LCIOReader
## EDM4hep
https://github.com/key4hep/EDM4hep/pulls
### Make tag to propagate doxygen
Merged: https://github.com/key4hep/EDM4hep/pull/110
### EDM4hep documentation page moved
### EDM4hep tools
https://github.com/key4hep/EDM4hep-utils
### Issues
### Need review of EDM4hepDelphes output
* Output is not stored if no tracks or towers created (?)
* Allow also other types to be part of the list
* Allow construction in a more general way (VV)
* Need to assume there is a complete list of reconstructed particles?
* Relations:
* FCCSW: Issue with more than one RecoParticle pointing to one MCParticle
* In LCIO to Delphes, conversion happens later than in edm4hep, maybe delphes does de-duplication?
* TODO: open issue in edm4hep with reproducer (VV)
--> Moving to separate repository
### PRs
https://github.com/key4hep/EDM4hep/pulls/
### Release 1.0
## AOB
### Conditions handling in Belle2
* Benedikt, or Martin Ritter
### Next meeting:
* March 8, 2021
### TODO
### New tags for k4SimDelphes
* Updated podio
* Updated Delphes version
* Update spack fork and main spack
### Key4hep presentation IAS
* Also add a link to the FCC presentation https://indico.cern.ch/event/934666/contributions/4154228/ from Epiphany