RESET SLAVE statement can be
used to reset a multi-source replication slave. By default, if you
RESET SLAVE statement on a
multi-source replication slave all channels are reset. Optionally,
clause to reset only
a specific channel.
To reset all currently configured replication channels:
To reset only a named channel, use a
RESET SLAVE FOR CHANNEL "master_1";
RESET SLAVE makes the slave forget
its replication position, and clears the relay log, but it does
not change any replication connection parameters (such as the
master host) or replication filters. If you want to remove these
for a channel, issue
RESET SLAVE ALL.