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WP4: EOSC Science Cluster Pilots and Driver projects

Pilot: Track Reconstruction using ACTS

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WP4 meeting

29 May 2024 - Online (Zoom) - indico:

Jawahar, Pratik

[he/him]

UniMan/CERN

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This project has received funding from the European Union’s Horizon Europe Programme under GA 101129744 — EVERSE — HORIZON-INFRA-2023-EOSC-01-02

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Track Reconstruction

The process involves:

  • Assessing the interaction of charged particles passing through layers of sensitive detectors
  • Extracting properties of the particle based on these interactions
    • This is accomplished by reconstructing the trajectory of the particle and assessing parameters such as the curvature under the specified magnetic field
  • These extracted trajectories and particle properties form a basic set of inputs to other high-level reconstruction procedures

As a result, track reconstruction is an essential component of physics analyses at most HEP experiments

Extracting properties of charged particles by connecting hits along different layers of the detector

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Track Reconstruction

Track reconstruction is a compute-intensive problem!

  • For the HL-LHC, ATLAS expects to have O(10,000) tracks per bunch crossing
    • Need to reconstruct ~10,000 tracks at ~100kHz
  • Software needs to provide reconstructions with as high resolution as possible, while being fast
    • Better tracking efficiency is essential for the Physics tasks downstream
  • Software also needs to efficiently resolve ambiguous track candidates
  • ATLAS is currently working on integrating ACTS (ACTS Common Tracking Software) into the production reconstruction software (ATHENA)
    • ACTS is an experiment-independent, open source track reconstruction software toolkit

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ACTS

(1) Describe the community that uses the software in your pilot

  • Developed by a team of Physicists and Computer Scientists at CERN
    • The collaboration has an organized core developer team
    • Benefits from multiple small scale projects by independent groups
      • These projects can be merged into the main repo if deemed to be useful
  • Used mainly by HEP experiments at the LHC (predominantly ATLAS) - Expert Physicists, Software Developers
    • Currently in the process of deploying ACTS into core ATLAS reconstruction software
  • Main repo: ACTS

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ACTS

(2) Describe the technical aspects of the code in your pilot

  • Software Tier - Tier 3: Research Software Infrastructure (Services included)
  • Technical Specs:
    • Language:
      • Source: Modern C++
      • Python bindings available
    • Size of codebase:
      • ~420k LOC (LOC counter for github repos)
    • Where does it run:
      • Documentation provides recipes to run via:
        • LCG release on CernVM File System (CVMFS)
        • Docker images
      • Building and installation is via CMAKE
        • Ideally, can install on local machine if prerequisites are satisfied
          • Long list of dependencies
        • However the documentation doesn't provide a specific recipe for this method

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ACTS

  • How has it been developed so far?:
    • Version control:
      • Git
    • Contribution guidelines:
      • Code guidelines
  • How does ACTS onboard new devs/users
    • The dev team hosts regular workshops (eg. ACTS Dev Workshop '22) that include hands-on tutorial sessions that explain different components of the toolkit:
      • Basic installation and examples
      • Using 3rd party plugins
      • Integrating custom pieces of code on top of the core library etc.
    • For ACTS-ATLAS integration specifically
      • Annual Dev Workshop

(3) Describe your software lifecycle:

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ACTS

(4) Are there indicators and tools applicable to your pilot(s) that provide insight into technical quality?

  • Static analysis tools:
    • SonarCloud
      • Cloud based
      • Provides varied insights on:
        • Issues
        • Complexity
        • Maintainability etc
      • Analysis performed by Tashif Bashir, Dr. Colin Venters (Uni Huddersfield)
      • Paper expected soon on best SW practices with ACTS as case study
  • Profiling:
    • gperftools (prof.) + pprof (viz.)
    • Valgrind - Mem profiling
    • NSight suite by NVIDIA
  • Codecov: Test coverage

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ACTS

(4) Are there indicators and tools applicable to your pilot(s) that provide insight into technical quality?

  • Static analysis tools:
    • SonarCloud
      • Cloud based
      • Provides varied insights on:
        • Issues
        • Complexity
        • Maintainability etc
      • Analysis performed by Tashif Bashir, Dr. Colin Venters (Uni Huddersfield)
      • Paper expected soon on best SW practices with ACTS as case study
  • Profiling:
    • gperftools (prof.) + pprof (viz.)
    • Valgrind - Mem profiling
    • NSight suite by NVIDIA
  • Codecov: Test coverage

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ACTS

(5) Describe the FAIR / Open aspects of the code in your pilot(s):

  • Repository: ACTS - Github
  • License: MPLv2
  • Citeable: Link
  • Discussion Community: Link
  • Software Quality Checklist: Link
  • Documentation:
    • Written and maintained by core dev team
    • Checklist for writing new documentation: Link
    • Documentation can also be built locally

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ACTS

(6) Does your software have a sustainability plan?

  • The project is open-sourced and was initially based on the ATLAS tracking software
  • The core team is predominantly based at CERN, with numerous other short term collaborators all over the world

(7) In your community, do you already have/know of training resources for developing/using software?

  • The project mostly follows the C++ Core Guidelines, with chosen naming conventions and formatting guidelines listed in the contribution guidelines

(8) How are software developers rewarded in your community?

  • Contributors are added to the list of authors
  • Significant scientific contribution can result in talks at conferences or the publication of research papers where due authorship is given to contributors

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Association to EVERSE

  • We are happy to connect all 3 pilots presented today to the EVERSE project both in terms of development of the project and implementing the outcomes of the project
  • UniMan is also currently in the process of hiring a PDRA whose main focus will be software sustainability for multiple projects UniMan is involved in

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Thank you!

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Contact details for meeting announcements (ask us to subscribe):

everse-wp4@lists.certh.gr

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WP leads:

Caterina Doglioni: caterina.doglioni@manchester.ac.uk

Guido Juckeland: g.Juckeland@hzdr.de

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This project has received funding from the European Union’s Horizon Europe Programme under GA 101129744 — EVERSE — HORIZON-INFRA-2023-EOSC-01-02

WP4 Pilot: ACTS - 29/05/2024 | P. Jawahar