2023.10.19 Meeting Notes

Agenda

Individual/group updates
API forward compatibility, see https://github.com/parthenon-hpc-lab/parthenon/issues/951
Next developer/user(?) meeting
review non-WIP PRs

LR

GMG was planned to be merged BUT discovered an issue with MPI and AMR
Running on different ranks results in different results. Now into debugging -- likely related to reusing comm buffers.
PR for cleanup GMG example and separating solver interface ready for review

BP

working through long KHARMA backlog related to restructuring (PEP1, bound conditions, ...)
found AMR bug (but currently expected to be an issue inside KHARMA)

PM

BW

while working on AthenaPK, came across API issue, raising question on forward compatibility (see discussion below)
trying to add FPE traps, but those don't work for MacOS. Will open PR that works on other architectures

PG

INCITE runs are going well (finally) though analysis is tough given the data volume
added in-situ histograms and "analysis restarts" to Parthenon to mitigate some of the analysis issue (with Ascent, Paraview, and yt)
PRs are ready for review though the "analysis restart" should be considered PEPish, so more a discussion with an example implementation

PG didn't properly communicate API breaking changes when updating AthenaPK to latest Parthenon
This raised a discussion on fixing the API and release cycles
Tentative results of the discussion (to be revisited at the next meeting)
- Parthenon is still evolving and we do not want to force ourselves in maintaining an API that is incompatible with a new feature
- we should make tagged releases roughly every 6 months and keep the API stable in between
- to keep the overhead small, we could add automated downstream compatibility tests (literally, continuous "integration") so flag PRs that break downstream codes
- when releasing the API breaking changes should be well documented so that downstream codes can easily adjust