We need to obtain the Raft ID of the replaced node during the shadow round and
place it in the address map. It won't be placed by the regular gossiping route
if we're replacing using the same IP, because we override the application state
of the replaced node. Even if we replace a node with a different IP, it is not
guaranteed that background gossiping manages update the address map before we
need it, especially in tests where we set ring_delay to 0 and disable
wait_for_gossip_to_settle. The shadow round, on the other hand, performs a
synchronous request (and if it fails during bootstrap, bootstrap will fail -
because we also won't be able to obtain the tokens and Host ID of the replaced
node).
Fetch the Raft ID of the replaced node in `prepare_replacement_info`,
which runs the shadow round. Return it in `replacement_info`. Then
`join_token_ring` passes it to `setup_group0`, which stores it in the
address map. It does that after `join_group0` so the entry is
non-expiring (the replaced node is a member of group 0). Later in the
replace procedure, we call `remove_from_group0` for the replaced node.
`remove_from_group0` will be able to reverse-translate the IP of the
replaced node to its Raft ID using the address map.
Also remove an unconditional 60 seconds sleep from the replace code. Make it
dependent on ring_delay.
Enable the replace tests.
Modify some code related to removing servers from group 0 which depended on
storing IP addresses in the group 0 configuration.
Closes#12172
* github.com:scylladb/scylladb:
test/topology: enable replace tests
service/raft: report an error when Raft ID can't be found in `raft_group0::remove_from_group0`
service: handle replace correctly with Raft enabled
gms/gossiper: fetch RAFT_SERVER_ID during shadow round
service: storage_service: sleep 2*ring_delay instead of BROADCAST_INTERVAL before replace