Post fails for low-resolution experiments

[WalterKolczynski-NOAA]

Expected behavior
Post should run for any resolution.

Current behavior
When running C96, post fails with a too many MPI tasks, max is 96 stopping message. Presumably UPP is limiting the number of ranks to the resolution (hold over from spectral?)

Machines affected
Discovered on Orion, but presumably on every machine.

To Reproduce

1. Set up any experiment using C96 resolution
2. Confirm the gdaspost and/or gfspost tasks fail in the first full cycle
3. Check the outpost_gfs_${CDATE}_postcntrl_gfs_anl.xml file in ${DATA} to see the error message

[CoryMartin-NOAA]

I am not convinced this is fixed.
A C96 experiment in rocoto had 3 nodes, 40 processors on Orion. 120 PEs, wich 96 < 120, so it failed. My guess is the config.resources did something like:
126 -> 96 (for resolution) but then 96/40 = 3 (because of 40 PEs/node on Orion)

@WalterKolczynski-NOAA would it be possible to confirm this is working as you intended it to be by an XML generation test only? Otherwise, I think the post scripts have to be modified to call srun with only the right number of PEs.

[WalterKolczynski-NOAA]

Yeah, I've seen it too. I have a fix I just need to submit it. In env/ORION.env, change APRUN_NP in the post section to ${launcher} -n ${npe_post}

[CoryMartin-NOAA]

@WalterKolczynski-NOAA thanks, just wanted to make sure I wasn't going crazy/had a bad setup.

[WalterKolczynski-NOAA]

I think the fix did work, but then subsequent updates forced a different solution.

[KateFriedman-NOAA]

Taking this on.