Also beginning with MySQL 5.6, when using MySQL replication, masters and slaves know one
another's UUIDs. The value of a slave's UUID can be seen in the output of SHOW SLAVE HOSTS. Once
START SLAVE has been executed (but not before), the value of the master's UUID is available on the
slave in the output of SHOW SLAVE STATUS.
In MySQL 5.6.5 and later, a server's server_uuid is also used in GTIDs for transactions originating
on that server. For more information, see Section 16.1.3, “Replication with Global Transaction