I tried this example, it works greatly even on multiple machines. But I am trying to understand how these two parameters work, and what the mechanism is:
rdzv_endpoint="localhost:0", rdzv_backend="c10d"

Let us say I have two machines, now I used above two parameters to both machines. How does that work? localhost:0 seems really non-typical. Under the hood, how is etcd involved in this process?
Thanks a lot!