NEST Hackathon Q1 2022

This hackathon will result in the next time-based release: version 3.3.

Where: Gathertown

When: 2022-03-07 to 2022-03-11

Participants

Steffen Graber
Markus Diesmann
Jessica Mitchell
Hans Ekkehard Plesser
Stine Vennemo
Håkon Mørk
Susanne Kunkel
Jochen Eppler
Dennis Terhorst
Charl Linssen
Pooja Babu
Guido Trensch

The plan!

solve NEST 3 series multi-threading performance problem not presented in 2.14 and not depending on MPI
- Anno, Dennis, Jari and others have prepared this work by ruling out obvious potential causes, identifying a relevant section of the cause catched by a timer, and providing real-world test scenario with short turn-around times
Get NEST 3.3 ready
- Go through list and sort milestone
review all PRs
NEST CI testing
- CMake configurable C++ version (#2319) was merged; next: discuss CI integration (GT)
- Discuss CI integration of NEST and PyNN and long-term responsibility of PyNN-NEST
- Setup NEST docker testing in gitlab CI/CD (Steffen)
Versions of NEST dependencies (also documentation links)
https://github.com/nest/nest-simulator/issues/2060 (CL, PB)
ResetKernel, ResetNetwork
- "Save and restore" was a spinoff from this, but is fundamentally more difficult. We just want a "reset to simulation time zero".
- Can use get- and set-status calls for the model state. But would still have to clear the spikes "in flight" (and other internal state and buffers in the NEST kernel, as far as this is not already covered by SimulationManager::initialize())
- Add testing that repeated runs are bit-for-bit replicable
- @apdavison will join us for discussion (Thursday 11AM)
Automatic testing of code snippets in install instruction (see what Dennis has done so far) (Steffen)
JIT semantics for Connect (https://github.com/nest/nestml/issues/721)
Documentation: #2283 #2288 #2289
NEST3 installation via Conda (strange behaviour; memory leaks?)

Short report

NEST 3.3 milestone: 4 issues and 2 PRs left to resolve
14 PRs merged; 7 new ones opened
Very productive discussions:
- ResetNetwork semantics: reached agreement within NEST dev team and with Andrew Davison (PyNN) (https://github.com/nest/nest-simulator/issues/2337)
- Vectorization of neurons: exploratory discussions
- New variable names mapping API call syntax/format for JIT agreed on (https://github.com/nest/nestml/issues/721)
- revamping the CI pipeline: a lot more static checks; some static checks still skipped ("suppressed"), which will be re-enabled gradually. Fixed single clang-format version. Better staging. Documentation checks. Deployment (building wheels, etc.) will be taken up next hackathon.
- Debugging runtime performance issues: work is ongoing
- Group discussion on revamping documentation pages and nest-simulator.org: major re-org (planned for 3.3) and new theme (planned for 3.4).
- Conda fix: work in progress.