XIOS target version

[mo-marqh]

Hello All

as part of our Met Office porting activities, we're investigating memory performance issues with the revision of XIOS that is currently installed on Met Office hosts and recommended for testing with lfric_core & lfric_apps/lfric_atm

currently we are using
https://forge.ipsl.fr/ioserver/browser/XIOS/trunk?rev=2252

we are evaluating whether there are memory usage benefits available, particularly during data loading to initialise models, from adopting
https://forge.ipsl.fr/ioserver/browser/XIOS2/trunk?rev=2701

We have not yet confirmed compatibility nor suitability of this revision to support LFRic.
If we are able to establish compatibility & suitability, then we would be interested in moving the LFRic : XIOS target recommendation.

I will try to maintain an information feed on this topic within this discussion, and provide links to build and evaluation tickets as they arise.
We invite input from all interested parties across the partnership on how we effectively manage the LFRic : XIOS version dependency.

mark

[mo-marqh]

out MetOffice simit-spack repository contains a build recipe for this r2701 revision of XIOS:
https://github.com/MetOffice/simit-spack/commit/4fff99403adda8407c9a176987ef3df27d0a5d8d
https://github.com/MetOffice/simit-spack/pull/90

[Scott Wales (ScottWales)]

We've been using r2629 at NCI - https://github.com/MetOffice/ngmo-environments/blob/main/environments/lfric/spack.yaml. Happy to try r2701 if you can share the recipe - simit-spack is not visible to partners.

NCI staff have been doing some investigation into using XIOS 3 for improved performance, I'm not up to date with the status of that

[Wolfgang Hayek (tinyendian)]

We are using r2279 at NIWA with (relatively) good success. I also have a Spack recipe that includes a build variant with OASIS3-MCT integration, happy to share that if there is interest. It would probably be useful to consolidate such recipes across the partnership to avoid doubling up work (I don't have access to the simit-spack repo, unfortunately).

[mo-marqh]

thanks Scott Wales (@ScottWales) Wolfgang Hayek (@tinyendian)
that is useful context.

we have completed further testing with r2701 of XIOS which has shown some promise, and as yet no fundamental blockers. I'll keep you updated on how we get along with adoption and scheduling.

I can also ask about simit-spack repository access if that's helpful

[Wolfgang Hayek (tinyendian)]

Thanks mo-marqh access to simit-spack would be very useful for collaboration I think (and sorry for a slow reply, just returned from a conference)