H-Huang:

is there in the code snippet you sent. For a third party backend you need to register it and perform init process group on


Thanks, yes, I am registering a third-party backend as in the document you’ve shared.
What I am referring to is the new_group() method in a ProcessGroup.
This allows to create a subgroup from the default process group by taking on a list of ranks. This list is referred to as the group_ranks in the _new_process_group_helper() method I pointed above.
My question was that this group_ranks list is not passed to the custom backend method. Instead, only the rank and world_size are passed.
Sees like a missing feature here.