Replication Channels 17.2.2.2 Compatibility with Previous Replication Statements Warning 17.2.2.3 Startup Options and Replication Channels When a replica has multiple channels and a  FOR CHANNEL  channel  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: Use  RESET REPLICA | 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 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  FOR CHANNEL  channel  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. This section describes startup options which are impacted by the addition of replication channels. The  master_info_repository  and  relay_log_info_repository  system variables must  not  be set to  FILE  when you use replication channels. In MySQL 8.0, the  FILE  setting is deprecated, and  TABLE  is the default, so the system variables can be omitted. From MySQL 8.0.23, they must be omitted because their use is deprecated from that release. If these system variables are set to  FILE , attempting to add more sources to a replica fails with  ER_SLAVE_NEW_CHANNEL_WRONG_REPOSITORY . The following startup options now affect  all  channels in a replication topology. All transactions received by the replica (even from multiple sources) are written in the binary log. 3594 • --relay-log-purge • --log-slave-updates • MASTER_POS_WAIT() • CHANGE MASTER TO • CHANGE REPLICATION SOURCE TO • SHOW RELAYLOG EVENTS • START REPLICA | SLAVE  starts replication threads for all channels, except the group_replication_recovery  and  group_replication_applier  channels. • STOP REPLICA | SLAVE  stops replication threads for all channels, except the group_replication_recovery  and  group_replication_applier  channels. • SHOW REPLICA | SLAVE STATUS  reports the status for all channels, except the group_replication_applier  channel. • RESET REPLICA | SLAVE  resets all channels.