Lfric2lfric multi cpu test

[Juan Manuel Castillo Sanchez (ukmo-juan-castillo)]

PR Summary

Sci/Tech Reviewer:
Code Reviewer: mo-marqh

This PR simply adds rose stem tests to compare running lfric2lfric with multiple CPUs.

• blocked-by Lfric2lfric w2 #390
• closes lfric2lfric: add multi CPU tests #366
• fixes lfric2lfric: add multi CPU tests #366
• is related to lfric2lfric: run with multiple CPUs #192

Code Quality Checklist

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• Comments have been included that aid understanding and enhance the readability of the code
• My changes generate no new warnings
• All automated checks in the CI pipeline have completed successfully

Testing

• I have tested this change locally, using the LFRic Apps rose-stem suite
• If any tests fail (rose-stem or CI) the reason is understood and acceptable (e.g. kgo changes)
• I have added tests to cover new functionality as appropriate (e.g. system tests, unit tests, etc.)
• Any new tests have been assigned an appropriate amount of compute resource and have been allocated to an appropriate testing group (i.e. the developer tests are for jobs which use a small amount of compute resource and complete in a matter of minutes)

Test Suite Results - lfric_apps - lfric2lfric_multi_CPU_test/run1

Suite Information

Item	Value
Suite Name	lfric2lfric_multi_CPU_test/run1
Suite User	juan.m.castillo
Workflow Start	2026-03-29T10:01:35
Groups Run	lfric2lfric', 'scripts

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.03.2	True
jules	MetOffice/jules@2026.03.2	True
lfric_apps	ukmo-juan-castillo/lfric_apps@lfric2lfric_multi_CPU_test	False
lfric_core	MetOffice/lfric_core@018e40c	True
moci	MetOffice/moci@2026.03.2	True
SimSys_Scripts	MetOffice/SimSys_Scripts@4387949	True
socrates	MetOffice/socrates@2026.03.2	True
socrates-spectral	MetOffice/socrates-spectral@2026.03.2	True
ukca	MetOffice/ukca@2026.03.2	True

Task Information

✅ succeeded tasks - 106

I just run the lfric2lfric tests as they are the only ones affected by these changes. I compared results with #275 and they do not change. Output generated with 1 CPU and multiple CPUs is the same.

Security Considerations

• I have reviewed my changes for potential security issues
• Sensitive data is properly handled (if applicable)
• Authentication and authorisation are properly implemented (if applicable)

Performance Impact

• Performance of the code has been considered and, if applicable, suitable performance measurements have been conducted

AI Assistance and Attribution

• Some of the content of this change has been produced with the assistance of Generative AI tool name (e.g., Met Office Github Copilot Enterprise, Github Copilot Personal, ChatGPT GPT-4, etc) and I have followed the Simulation Systems AI policy (including attribution labels)

Documentation

• Where appropriate I have updated documentation related to this change and confirmed that it builds correctly

PSyclone Approval

• If you have edited any PSyclone-related code (e.g. PSyKAl-lite, Kernel interface, optimisation scripts, LFRic data structure code) then please contact the TCD Team

Sci/Tech Review

• I understand this area of code and the changes being added
• The proposed changes correspond to the pull request description
• Documentation is sufficient (do documentation papers need updating)
• Sufficient testing has been completed

(Please alert the code reviewer via a tag when you have approved the SR)

Code Review

• All dependencies have been resolved
• Related Issues have been properly linked and addressed
• CLA compliance has been confirmed
• Code quality standards have been met
• Tests are adequate and have passed
• Documentation is complete and accurate
• Security considerations have been addressed
• Performance impact is acceptable

[Lottie Turner (mo-lottieturner)]

It looks like checksum_lfric2lfric_oasis_clim_gal9_C12-ral_seuk_C16_lam-lbc_4cpu_azspice_gnu_fast-debug-64bit.txt is the same as checksum_lfric2lfric_oasis_clim_gal9_C12-ral_seuk_C16_lam-lbc_1cpu_azspice_gnu_fast-debug-64bit.txt - have you checked the other new kgos to see if they are the same as their single-cpu equivalents?

[Lottie Turner (mo-lottieturner)]

Hi Juan. Thanks for making those changes - just to note, as per the working practices, the developer should not be resolving comments left by others

[Lottie Turner (mo-lottieturner)]

Hi Juan. I think this is still too many multi-cpu tests in the developer group. Remember that the all group is run nightly, so issues with scaling will still be caught. Can you start by moving all of the new tests into the extra group, and then pick one of them to move back into the ex1a developer group?