Hypergraph

[lkotipal]

• Add Zoltan Graph/Hypergraph support to Vlasiator, requires Hypergraph dccrg#27
• Neighborhood used for hypergraph partitioning is parametrized as loadBalance.partitioning_neighborhood, defaulting to the full neighborhood encompassing extended sysboundaries and Vlasov translation.

[lkotipal]

So here are some profiling results. HYPERGRAPH seems to outperform RCB but loses to RIB in this test using samples/Magnetosphere3D on 8 Mahti nodes. Let me know if you want more numbers.

EDIT: numbers outdated, but results are still the same

[markusbattarbee]

Some less and some more serious questions

[markusbattarbee]

Neighborhood names need to be updated to be in accordance with the changes from #1020

[markusbattarbee]

some lingering depracted stuff from merges

[ursg]

This (and the corresponding DCCRG PR) looks all sane when reading throuh, and your results indicate that it at least doesn't break anything.

But I agree with Markus that a small at-scale test, especially in interaction with dAMR, should be done before merging.