fail.

For example:

STOP SLAVE;
CHANGE MASTER TO
 MASTER_HOST='dbserver1.example.com',
 MASTER_USER='repl',
 MASTER_PASSWORD='new3cret',
 MASTER_USE_GTID=slave_pos;
START SLAVE;

If you set the value of the MASTER_HOST option in a CHANGE MASTER command,
then the replica assumes that the primary is different from before, even if
you set the value of this option to the same value it had previously. In this
scenario, the replica will consider the old values for the primary's binary
log file name and position to be invalid for the new primary. As a side
effect, if you do not explicitly set the values of the MASTER_LOG_FILE and
MASTER_LOG_POS options in the statement, then the statement will be implicitly
appended with MASTER_LOG_FILE='' and MASTER_LOG_POS=4. However, if you enable
GTID mode for replication by setting the MASTER_USE_GTID option to some value
other than no in the statement, then these values will effectively be ignored
anyway.

Replicas cannot connect to primaries using Unix socket files or Windows named
pipes. The replica must connect to the primary using TCP/IP.

The maximum length of the MASTER_HOST string is 60 characters until MariaDB
10.5, and 255 characters from MariaDB 10.6.

MASTER_PORT
-----------

The MASTER_PORT option for CHANGE MASTER defines the TCP/IP port of the
primary.

For example:

STOP SLAVE;
CHANGE MASTER TO
 MASTER_HOST='dbserver1.example.com',
 MASTER_PORT=3307,
 MASTER_USER='repl',
 MASTER_PASSWORD='new3cret',
 MASTER_USE_GTID=slave_pos;
START SLAVE;

If you set the value of the MASTER_PORT option in a CHANGE MASTER command,
then the replica assumes that the primary is different from before, even if
you set the value of this option to the same value it had previously. In this
scenario, the replica will consider the old values for the primary's binary
log file name and position to be invalid for the new primary. As a side
effect, if you do not explicitly set the values of the MASTER_LOG_FILE and
MASTER_LOG_POS options in the statement, then the statement will be implicitly
appended with MASTER_LOG_FILE='' and MASTER_LOG_POS=4. However, if you enable
GTID mode for replication by setting the MASTER_USE_GTID option to some value
other than no in the statement, then these values will effectively be ignored
anyway.

Replicas cannot connect to primaries using Unix socket files or Windows named
pipes. The replica must connect to the primary using TCP/IP.

MASTER_CONNECT_RETRY
--------------------

The MASTER_CONNECT_RETRY option for CHANGE MASTER defines how many seconds
that the replica will wait between connection retries. The default is 60.

STOP SLAVE;
CHANGE MASTER TO 
 MASTER_CONNECT_RETRY=20;
START SLAVE;

The number of connection attempts is limited by the master_retry_count option.
It can be set either on the command-line or in a server option group in an
option file prior to starting up the server. For example:

[mariadb]
...
master_retry_count=4294967295

MASTER_BIND
-----------

The MASTER_BIND option for CHANGE MASTER is only supported by MySQL 5.6.2 and
later and by MySQL NDB Cluster 7.3.1 and later. This option is not supported
by MariaDB. See MDEV-19248 for more information.

The MASTER_BIND option for CHANGE MASTER can be used on replicas that have
multiple network interfaces to choose which network interface the replica will
use to connect to the primary.

MASTER_HEARTBEAT_PERIOD
-----------------------

The MASTER_HEARTBEAT_PERIOD option for CHANGE MASTER can be used to set the
interval in seconds between replication heartbeats. Whenever the primary's
binary log is updated with an event, the waiting period for the next heartbeat
is reset.

This option's interval argument has the following characteristics:

* It is a decimal value with a range of 0 to 4294967 seconds.
* It has a resolution of hundredths of a second.
* Its smallest valid non-zero value is 0.001.
* Its default value is the value of the slave_net_timeout system variable
divided by 2.
* If it's set to 0, then heartbeats are disabled.

Heartbeats are sent by the primary only if there are no unsent events in @RñÉ