Syntax:
{SHOW REPLICAS | SHOW SLAVE HOSTS}

Displays a list of replicas currently registered with the source. From
MySQL 8.0.22, use SHOW REPLICAS in place of SHOW SLAVE HOSTS, which is
deprecated from that release. In releases before MySQL 8.0.22, use SHOW
SLAVE HOSTS. SHOW REPLICAS | SHOW SLAVE HOSTS requires the REPLICATION
SLAVE privilege.

SHOW REPLICAS | SHOW SLAVE HOSTS should be executed on a server that
acts as a replication source. The statement displays information about
servers that are or have been connected as replicas, with each row of
the result corresponding to one replica server, as shown here:

mysql> SHOW REPLICAS;
+------------+-----------+------+-----------+--------------------------------------+
| Server_id  | Host      | Port | Source_id | Replica_UUID                         |
+------------+-----------+------+-----------+--------------------------------------+
|         10 | iconnect2 | 3306 |         3 | 14cb6624-7f93-11e0-b2c0-c80aa9429562 |
|         21 | athena    | 3306 |         3 | 07af4990-f41f-11df-a566-7ac56fdaf645 |
+------------+-----------+------+-----------+--------------------------------------+

o Server_id: The unique server ID of the replica server, as configured
  in the replica server's option file, or on the command line with
  --server-id=value.

o Host: The host name of the replica server, as specified on the
  replica with the --report-host option. This can differ from the
  machine name as configured in the operating system.

o User: The replica server user name, as specified on the replica with
  the --report-user option. Statement output includes this column only
  if the source server is started with the --show-slave-auth-info
  option.

o Password: The replica server password, as specified on the replica
  with the --report-password option. Statement output includes this
  column only if the source server is started with the
  --show-slave-auth-info option.

o Port: The port on the source to which the replica server is
  listening, as specified on the replica with the --report-port option.

  A zero in this column means that the replica port (--report-port) was
  not set.

o Source_id: The unique server ID of the source server that the replica
  server is replicating from. This is the server ID of the server on
  which SHOW REPLICAS | SHOW SLAVE HOSTS is executed, so this same
  value is listed for each row in the result.

o Replica_UUID: The globally unique ID of this replica, as generated on
  the replica and found in the replica's auto.cnf file.

URL: https://dev.mysql.com/doc/refman/8.0/en/show-replicas.html

