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HSF Weekly Meeting #167, 6 June, 2019

Present/Contributors: Graeme Stewart, Pere Mato, Witek Pokorski, Daniel Elvira, Andrea Rizzi, Michel Jouvin, Martin Ritter, Paul Laycock, Gloria Corti, Caterina Doglioni

Apologies: Agnieszka Dziurda

News, general matters

• LHCC this week, Graeme gave the software presentation update:
  • https://indico.cern.ch/event/754732/
  • Thanks to everyone for comments and suggestions.
  • Feedback during the meeting:
    1. Generators - emphasise to the generator developers that negative event weights have a huge adverse effect (are there ways to minimise this by tackling the phase space differently?)
       • A. Pass this message on via EG WG.
    2. ML Simulation of calorimeters - will the work be portable to different detectors?
       • A. We understand this is the intention of the OpenLab/SFT efforts, but not yet there; for future R&D.
    3. Accelerators - do people develop the code in portable ways, avoiding tuning to a particular GPU architecture?
       • A. This is an issue people are aware of - try to separate physics code from device code. R&D starting on abstraction layers to insulate us a bit more. (CMS showed some work with Kokkos and Alpaka that looked quite hopeful.)
  • Referees’ Recommendations (with emphasis for software issues):
    1. 2021 requirements should be firmed up, based on the latest understanding of the likely machine performance.
    2. A timetable for Phase-2 computing model reviews should now be established.
    3. Discussions with funding agencies should continue, regarding the provision of resources when future cost estimates are very uncertain.
    4. The discussion around the use of HPC should continue. How can we adapt to use HPC resources and/or have more influence over how they are setup?
    5. Work on hardware acceleration (GPU, FPGA) holds the promise of a big leap in performance. This work should be encouraged and coordinated across experiments.
• Simulation on accelerators caught people’s eye for sure. We have to take this seriously and do R&D, but not allow inflated expectations. x100 speed-ups are not going to come and the costs of the re-coding will be enormous. We should discuss this seriously because HSF can help to coordinate answers here.

Google Summer of Code 2019

• Coding period has started.

Google Season of Docs

• In proposal period.

Activity and Working Group Updates

Data Analysis

• Nothing particular to report. Discussions ongoing in multiple threads on the google groups

Detector Simulation

• Topical meeting next week on geometry.
  • DD4hep, Geometry optimisation in ATLAS, VecGeom.
• There is a topic of CAD->GDML tool, but probably no time for it next week.
• Foresee another geometry meeting after the summer, but with a different focus, e.g., visualisation of geometry.

Reconstruction and Software Triggers

• Yesterday’s topical meeting: https://indico.cern.ch/event/823263/
• Topic: Algorithmic approaches and data structures to efficiently exploit accelerators and many-core architectures
• LHCb presented their experience: reached the milestone of 30MHz after SoA/SIMD event model changes.
• Meeting very well attended ~50 people.
• Presentations very well received - a lively discussion (meeting took 2h!)
• Request to follow up SoA/AoS with ATLAS/CMS
• Live notes: https://docs.google.com/document/d/1IcvpsgOPpVfaBeZpSCcKD6i1y4HesA-VJopOYV4S_7c/edit (still needs to be filled and cleaned in some places)
• To-do: need to add indico/lives notes to the website

Software Tools

• Organising meeting following up on potential meeting topics with speakers.

Training

• New training Indico category created at HSF top level:
  • https://indico.cern.ch/category/5816/.
• Need to follow up on possible training events at CERN.

Packaging

• Meeting 29 May, minutes available:
  • https://hepsoftwarefoundation.org/organization/2019/05/29/packaging.html
• Next meeting planned for 3 July.

Frameworks

• Reminder that call for nominations is open until tomorrow.
  • Mandate: https://hepsoftwarefoundation.org/workinggroups/frameworks.html
• So far 10 nominations received.
• Some people who are HSF Coordinators, so we will establish a search committee again to propose from the nominees.

Workshops

Pre-CHEP (2-3 November)

• Organising meeting happened this week: Document created to track decision and progress.
• Proposed title: Analysis Systems: From Future Facilities to Final Plots.
• Main high-level items for the HSF and DOMA sides identified: we have a good list!
  • Still have to group them into sessions: goal is to mix HSF and DOMA topics in each session so that the full audience is motivated to attend the whole event.
• Drafting a description of the workshop for the next CHEP bulletin planned before the end of June.
  • Will also start to fill blocks in Indico and refine them as soon as we progress with session definitions.
  • Saturday will be 1-6pm, Sunday will be 9am - 1pm.

Next HSF/WLCG Workshop

• We are making a formal call now for interest in hosting this event. Parameters are:
  • Facilities for 1 whole week, in May or June 2020
    • Monday morning -> Friday lunchtime
    • Known weeks to try to avoid so far: w/b 18 May (Ascension Holiday); w/b 1 June (LHCC); w/b 22 June (ATLAS Week)
  • 1 plenary room, capacity min 250
  • 2 additional parallel rooms, capacity min 100 each
  • Vidyo connection in these 3 rooms for the week
  • Optional breakout rooms ~3x30 people would be nice (vidyo there optional)
  • Low costs favoured (€200 ideal, €300 acceptable)
  • Lunch options to be specified - on site and included in registration favoured
  • One reception event on Monday, costs included; one dinner, could be billed separately if necessary
  • Some indications of typical local accommodation costs and travel options
  • A European location is favoured this time
• Please express interest by 12 July to hsf-coordination@googlegroups.com.
• We will need a small organising team for HSF.

AOB

• ECFA special session at EPS-HEP on “Toward the Update of the European Particle Physics Strategy” (13 July).
  • Graeme invited to give the talk on Computing and Software challenges.
• AIDA++ follow up call for expressions of interest has been made. There is a f2f meeting at CERN on 17-18 June:
  • https://indico.cern.ch/event/822748/.
  • Contact Witek, Frank and Graeme to make an EoI (due beginning of July) and plan to attend that meeting if possible as it will help to build a consistent program.
  • Note, you can attend the meeting even if you do not have an EoI to present. General input from the community is important to define the right programme.
• Having coordination meetings every two weeks seems to be a good rhythm at the moment.
  • Should we formalise this and adjust the meeting planning from now on?
  • It frees this slot for any WG that wants it.
  • We can always have an additional “odd” coordination meeting again as needed.
  • Agreed that we try this cadence for now.
  • -> Next meeting 20 June.

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