MySQL 5.7 Reference Manual
MySQL 5.7 Release Notes
These steps assume you have enabled GTIDs for transactions on the
replication source servers using
gtid_mode=ON, created a
replication user, ensured that the replica is using
TABLE based replication metadata repositories,
and provisioned the replica with data from the sources if
appropriate.
Use the CHANGE MASTER TO statement
to configure a replication channel for each source on the replica
(see Section 5.2, “Replication Channels”). The FOR
CHANNEL clause is used to specify the channel. For
GTID-based replication, GTID auto-positioning is used to
synchronize with the source (see
Section 2.3.3, “GTID Auto-Positioning”). The
MASTER_AUTO_POSITION option is set to specify
the use of auto-positioning.
For example, to add source1 and
source2 as sources to the replica, use the
mysql client to issue the
CHANGE MASTER TO statement twice on
the replica, like this:
mysql> CHANGE MASTER TO MASTER_HOST="source1", MASTER_USER="ted", \
MASTER_PASSWORD="password", MASTER_AUTO_POSITION=1 FOR CHANNEL "source_1";
mysql> CHANGE MASTER TO MASTER_HOST="source2", MASTER_USER="ted", \
MASTER_PASSWORD="password", MASTER_AUTO_POSITION=1 FOR CHANNEL "source_2";
For the full syntax of the CHANGE MASTER
TO statement and other available options, see
CHANGE MASTER TO Statement.