rank_zero only logic

[itzsimpl]

In line

pytorch-lightning/src/lightning/fabric/utilities/rank_zero.py

Line 42 in b3c869f

rank_keys = ("RANK", "LOCAL_RANK", "SLURM_PROCID", "JSM_NAMESPACE_RANK")

is the use of LOCAL_RANK intentional? Will this not lead to different behaviour depending on the environment? RANK, SLURM_PROCID and JSM_NAMESPACE_RANK are global rank, LOCAL_RANK is node local.

In a multi-node setup, assuming LOCAL_RANK is set then depending on RANK being set or not this may lead to rank_zero_only execute on global rank 0 or local rank 0.