• Preamble
• Overall Activity and Coordination
  • Meeting Series
  • Workshops
  • Organisational Engagement
  • Software Projects
  • Post-CWP and LHCC
• Working Groups
  • Data Analysis
  • Detector Simulation
  • Reconstruction and Software Triggers
  • PyHEP
  • Software Tools and Packaging
  • Software Training
  • Event generators
  • Frameworks

Preamble

In the first few meetings of 2021 the HSF established some high-level plans and goals for 2021. While none of these are cast in stone, we remain agile to adapt to new opportunities and circumstances throughout the year, they are a useful guide to our activities.

We encourage experiments and projects to take a look at these and we welcome any suggestions about how to make the HSF more effective and useful in HEP and for allied fields.

Overall Activity and Coordination

• Reference: 7 January 2021 slides and meeting minutes.*

Meeting Series

• Continue with regular coordination meetings every 2 weeks (on the odd-numbered weeks of the year by default).
• Monthly Software and Computing Roundtable is an ideal place to speak to the Nuclear Physics community (BNL and JLab co-organise), but we should make sure the more widely known and undeline that it is not just for Nuclear Physics colleagues.
• Also monthly, the Compute Accelerator Forum made a very good start last year and attracts a lot of interest - good that it’s co-organised with SIDIS and openlab.

Workshops

• Although we had two successful workshops in 2020, there is a real sense of zoom-fatigue in the community.
  • Therefore we will not organise any large workshops in the first half of 2021.
  • There is a slot for a possible workshop at the end of September (w/b 27 Sept), but we don’t yet take a firm decision on that.
• We will consider more ‘one-shot’ mini-workshops that cover topics which bridge between working groups, e.g., I/O matters that touch analysis, frameworks and facilities.

Organisational Engagement

• We already have quite a long list of organisations with which we have a link or some engagement (see slide 11 of the presentation above).
  • Keep this up and be alert for additional opportunities.
  • In particular in the next ~year the Snowmass process will be important (this has been delayed by a year).

Software Projects

• It can be useful for projects to be associated with the HSF (e.g., listed as a project or making use of our GitHub organisation).
  • We should be alert to these opportunities, particularly when the working groups can identify areas of common interest or tools that can expand their user base.

Post-CWP and LHCC

• As we prepare activity for the year we should not forget to look back to the Community White Paper and see which plans there were put into place, by the HSF directly or in other contexts.

• We already did some of that in preparing last year’s LHCC review document.

  • This year Graeme and Liz have a role for the HSF/WLCG again in this process, so we remind people this can still be useful.

Working Groups

Reference: 21 January 2021 meeting minutes.

Data Analysis

Ongoing series of metadata discussions seems like a workable format to repeat on other topics. So this and other themes for 2021 could be:

• Metadata in analysis
  • Lots is needed and it’s often time consuming for analysts to find and verify all the data they need
  • There’s usually no standard way of doing this - lack of uniformity
  • Series of three meetings looking at different aspects of the metadata needed for analyses:
    • Calibrations and scale factors and cross-sections & other similar non-event data needed for analysis
    • Event processing & book-keeping
    • How this is all combined for an analysis
• Declarative analysis & analysis frameworks
  • Want to avoid this becoming a competition —> focus on interfaces & usability?
  • Incorporate workflow management as well as event processing
  • Identify the most essential functions of an analysis framework & how these should be provided to the user
  • Could have follow-up meeting or even mini-workshop to expand benchmarks (c.f. https://github.com/iris-hep/adl-benchmarks-index)
  • To-do: review what IRIS-HEP is up to, so we don’t duplicate
• Overviews from non-LHC experiments
  • We as conveners still lack some awareness of the major issues in some other communities
  • Thinking to invite reps from e.g. neutrinos, nuclear physics to describe what issues they are grappling with
• Reduced data formats (NanoAOD/DAOD_PHYSLITE)
  • Attempted conversations with the non-mainstream analyses
  • Should we revisit questions of policy (i.e. how to engage user base), consequences (framework design, sites)
  • Also haven’t spoken to WLCG/DOMA in a year (https://indico.cern.ch/event/890991/manage/timetable/#20200323), try to reconnect? But needed more concreteness on what studies should be done.

Besides these, we discussed commonalities with Training WG. One question: how much should HSF branch into (experiment-agnostic) analysis tutorials?

• Curriculum has a basic CMS example — without going heavily in on teaching physics, could this be expanded to cover statistical tools, demonstrate analysis ecosystem e.g. PyHEP? But don’t want to be prescriptive.
• (Probably) have had discussions comparing e.g. CMS DA school and ATLAS SW tutorial? Can HSF material usefully be integrated into these?

Detector Simulation

• Topics and cross-group areas:
  • Computational challenges in future detectors (e.g. muon colliders)
  • Use of GPUs and similar accelerators
  • Developments in ML for simulation
  • Simulation for liquid noble gas detectors (covering both neutrino and dark matter experiments)
  • Geometry: e.g. developments/experiences with DD4hep, VecGeom
  • Use of FLUKA/MARS by experiments
  • Dealing with pile-up (possible cross-link with Frameworks, Reconstruction?)
• Will keep in touch with Geant4 Task Force for R&D to avoid duplication and identify possible joint meetings
• Further ideas and input very welcome, especially for cross-WG items, e.g.
  • Use of Python with/for Simulation?
  • Training: link up with Geant4 material/courses?

Reconstruction and Software Triggers

• Areas of common interest (in general these are topics related to HL-LHC and off-LHC experiments, LHC Run 3 R&D is basically closed):
  • ML for and its integration into production code
    • Machine learning frameworks for performant inference engines in real-time supporting various hardware backends (possible links to fastML, clariphy, …)
    • make the step from conceptual studies to production code integration
  • Alignment / calibration
    • points of collaboration on “sharp knife” tools
  • Particle flow
    • was initially planned in last term but did not materialize
  • Event data formats and geometry (overlaps with other groups)
    • great possibility to have an overlap session with simulation
  • Use of heterogeneous architectures
    • establish small scale demonstrators outside the experiments’ structure
    • investigate inclusion of common HEP reconstruction & trigger packages into such systems
• Establish closer link to training group, expanding from pure technical training
  • e.g.: general introduction to HEP triggers and reconstruction and introduction to the methods used; can training be done on little demonstrators:
  • ALLEN demonstrator of multi-event scheduling framework for GPUs, allowing to interleave host(CPU) and device(CPU / AMD GPU / Nvidia GPU) algorithms, where the device type is chosen at compile time (same source code for all device types)
  • Patatrack, ACTS etc. on OpenDataDetector
• Help integrating common packages into turn-key demonstrator projects
  • natural connection: CERN EP-R&D turn-key (Key4hep)
• Short, one-day workshops on specific topic, with possible overlap between HSF working groups:
  • trigger/reconstruction & simulation (fast MC initiatives, EDM/Geometry)
  • trigger/reconstruction & analysis (no clear boundaries)
• Next Steps
  • Talk to trigger & reco conveners of experiments
    • last survey is ~1.5 years old
  • Talk to computing projects of experiments
  • Make sure to include non-LHC experiments

PyHEP

• PyHEP 2021 workshop:
  • Date to be decided. Likely just after SciPy 2021, which takes place as a virtual event on July 12-18.
• Topical meetings:
  • We are running this year a kind of “Python module of the month” meeting, by default the first Wednesday of each month at 16h CET.
  • Topics so far confirmed are, see Indico:
    • Feb 3rd: Numba, by Jim Pivarski.
    • March 3rd: JAX, by Hans Dembinski.
    • April 7th: pyhf, by Giordon, Lukas and Matthew.
  • We welcome suggestions of topics very much.

Software Tools and Packaging

• Packaging Topics
  • Follow-ups on Spack
    • With the Key4hep group
    • Efforts at Fermilab for LArsoft
  • See how other support projects are doing things
    • EESSI - European Environment for Scientific Software Installations
    • Compute Canada
• Tools
  • Static analysers
  • Profiling
    • Already started to discuss perf and plan a follow-up
  • IDEs

Software Training

• Plans for 2021:
  • Beef out the HSF curriculum https://hepsoftwarefoundation.org/training/curriculum.html
  • Nail down how to measure success (surveys?)
  • Encourage more people to integrate into the HSF Training community
  • Strengthen friendship with Software Carpentries
  • Collaborate with other HSF working groups to hold trainings
  • Emphasise the interplay between training and careers
• Hackathon is being actively followed up, to continue to develop material.

Event generators

• Complete the paper at last! (should be ready in ~few weeks)
• Arrange meetings to discuss work done by others as in the plans laid out in detail in the paper, many areas of work:
  1. Understanding of the current CPU costs by accounting and profiling.
     • There has been separate work on e.g. profiling MG5_aMC and Sherpa which actually show some common conclusions
     • Time to bring this together and compare more apples-to-apples * Look ahead to NNLO codes?
  2. Moving to GPUs/accelerators.
     • Continue effort on the MG5_aMC GPU port
     • Try to follow-up better on similar activities for other generators (e.g. Sherpa and Pythia8)
  3. Optimisation of phase space sampling and integration algorithms, including the use of ML
     • This is somewhere we have not yet made large inroads - it will become a larger focus.
     • Topical meeting for the WG.
  4. Reducing the cost associated with negative weight events
     • Quite some discussions on this already in the WG
     • In particular at the November WS * Next steps…?
     • Trying to get existing tools more integrated into generator/experiment/ workflows
  5. Promote collaboration, training, funding and career opportunities in the generator area: Collaboration
     • Build contacts with relevant projects:
     • E.g. Excalibur/SWIFT-HEP (UK) and HEP-CCE (US)
     • Offer a forum for communication between the two groups and help avoid overlaps? * Engage more with the Experiments?
     • There is work that has already been done but doesn’t always make it into the experiment workflows * Engage more with Nuclear people? Use contacts established via S&C Roundtable * Neutrino community - Liz has some contacts
• Career opportunities and funding
  • Not sure exactly what the WG can do here currently other than raise the visibility of the work through e.g. the paper and presentation at LHCC…
• Training
  • So far we have not been active in providing training
    • Should discuss this with HSF Training folks!
  • Need to think what that would look like…
    • E.g. would generator-specific code training be possible/make sense?
    • If not, do we need more “generic” training on e.g. programming for GPUs, profiling etc.?
      • This might be more the right emphasis from HSF.

Frameworks

• Have free-form-discussion meetings between the experiments once a month
  • First Wednesday of every month, starting on March 3rd
• Multi-meeting discussion about heterogeneous computing usage in experiment frameworks
  • Joint meeting with Packaging WG about build system / packaging aspects of heterogeneous software releases?
• Invite “DOE parallel I/O developers” to show what they are working on
• Discuss work to remove use of TBB deprecated APIs from frameworks
• Investigate whether guidance (e.g. webpages) can and should be assembled regarding framework aspects such as multithreading, metadata, offloading, etc.

---