MySQL 5.7 Release Notes
When a replication slave has multiple channels and a FOR
CHANNEL option
is not specified, a valid statement generally acts on all
available channels.
channel_name
For example, the following statements behave as expected:
START SLAVEstarts replication threads for all channels. (In MySQL 5.7.9 and later, this does not include thegroup_replication_recoverychannel.)STOP SLAVEstops replication threads for all the channels. (In MySQL 5.7.9 and later, this does not include thegroup_replication_recoverychannel.)SHOW SLAVE STATUSreports the status for all channels.FLUSH RELAY LOGSflushes the relay logs for all channels.RESET SLAVEresets all channels.
Warning
Use RESET SLAVE with caution as this
statement deletes all existing channels, purges their relay log
files, and recreates only the default channel.
Some replication statements cannot operate on all channels. In
this case, error 1964 Multiple channels exist on the
slave. Please provide channel name as an argument. is
generated. The following statements and functions generate this
error when used in a multi-source replication topology and a
FOR CHANNEL
option is not
used to specify which channel to act on:
channel_name
Note that a default channel always exists in a single source replication topology, where statements and functions behave as in previous versions of MySQL.