Replication Channels From MySQL 8.0, multi-source replicas can be configured with replication filters on specific replication channels. Channel specific replication filters can be used when the same database or table is present on multiple sources, and you only need the replica to replicate it from one source. For GTID-based replication, if the same transaction might arrive from multiple sources (such as in a diamond topology), you must ensure the filtering setup is the same on all channels. For more information, see Section 17.2.5.4, “Replication Channel Based Filters” . To provide compatibility with previous versions, the MySQL server automatically creates on startup a default channel whose name is the empty string ( "" ). This channel is always present; it cannot be created or destroyed by the user. If no other channels (having nonempty names) have been created, replication statements act on the default channel only, so that all replication statements from older replicas function as expected (see Section 17.2.2.2, “Compatibility with Previous Replication Statements” . Statements applying to replication channels as described in this section can be used only when there is at least one named channel. To enable MySQL replication operations to act on individual replication channels, use the  FOR CHANNEL channel  clause with the following replication statements: An additional  channel  parameter is introduced for the following function: The following statements are disallowed for the  group_replication_recovery  channel: The following statements are disallowed for the  group_replication_applier  channel: FLUSH RELAY LOGS  is now permitted for the  group_replication_applier  channel, but if the request is received while a transaction is being applied, the request is performed after the transaction ends. The requester must wait while the transaction is completed and the rotation takes place. This behavior prevents transactions from being split, which is not permitted for Group Replication. 3593 • SHOW REPLICA | SLAVE STATUS • STOP REPLICA | SLAVE • START REPLICA | SLAVE • STOP REPLICA | SLAVE • START REPLICA | SLAVE • MASTER_POS_WAIT() • RESET REPLICA | SLAVE • SHOW REPLICA | SLAVE STATUS • FLUSH RELAY LOGS • SHOW RELAYLOG EVENTS • STOP REPLICA | SLAVE • START REPLICA | SLAVE • CHANGE MASTER TO • CHANGE REPLICATION SOURCE TO 17.2.2.1 Commands for Operations on a Single Channel