When a replica has multiple channels and a
option is not
specified, a valid statement generally acts on all available
channels, with some specific exceptions.
For example, the following statements behave as expected for all except certain Group Replication channels:
START REPLICAstarts replication threads for all channels, except the
STOP REPLICAstops replication threads for all channels, except the
SHOW REPLICA STATUSreports the status for all channels, except the
RESET REPLICAresets all channels.
REPLICA 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
replica. 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
option is not used to specify which channel to act on:
Note that a default channel always exists in a single source replication topology, where statements and functions behave as in previous versions of MySQL.