MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

13.4.2.4 RESET SLAVE Syntax

RESET SLAVE [ALL] [channel_option]

channel_option:
    FOR CHANNEL channel

RESET SLAVE makes the slave forget its replication position in the master's binary log. This statement is meant to be used for a clean start: It clears the master info and relay log info repositories, deletes all the relay log files, and starts a new relay log file. It also resets to 0 the replication delay specified with the MASTER_DELAY option to CHANGE MASTER TO.

Note

All relay log files are deleted, even if they have not been completely executed by the slave SQL thread. (This is a condition likely to exist on a replication slave if you have issued a STOP SLAVE statement or if the slave is highly loaded.)

For a server where GTIDs are in use (gtid_mode is ON), issuing RESET SLAVE has no effect on the GTID execution history. The statement does not change the values of gtid_executed or gtid_purged, or the mysql.gtid_executed table. If you need to reset the GTID execution history, use RESET MASTER, even if the GTID-enabled server is a replication slave where binary logging is disabled.

RESET SLAVE requires the RELOAD privilege.

To use RESET SLAVE, the slave replication threads must be stopped, so on a running slave use STOP SLAVE before issuing RESET SLAVE. To use RESET SLAVE on a Group Replication group member, the member status must be OFFLINE, meaning that the plugin is loaded but the member does not currently belong to any group. A group member can be taken offline by using a STOP GROUP REPLICATION statement.

The optional FOR CHANNEL channel clause enables you to name which replication channel the statement applies to. Providing a FOR CHANNEL channel clause applies the RESET SLAVE statement to a specific replication channel. Combining a FOR CHANNEL channel clause with the ALL option deletes the specified channel. If no channel is named and no extra channels exist, the statement applies to the default channel. Issuing a RESET SLAVE ALL statement without a FOR CHANNEL channel clause when multiple replication channels exist deletes all replication channels and recreates only the default channel. See Section 17.2.3, “Replication Channels” for more information.

RESET SLAVE does not change any replication connection parameters such as master host, master port, master user, or master password.

If you want to reset the connection parameters intentionally, you need to use RESET SLAVE ALL, which clears the connection parameters. In that case, you must issue a CHANGE MASTER TO statement after the server start to specify the new connection parameters.

RESET SLAVE ALL clears the IGNORE_SERVER_IDS list set by CHANGE MASTER TO.

RESET SLAVE does not change any replication filter settings (such as --replicate-ignore-table) for channels affected by the statement. However, RESET SLAVE ALLremoves the replication filters that were set on the channels deleted by the statement. When the deleted channel or channels are recreated, any global replication filters specified for the slave are copied to them, and no channel specific replication filters are applied. For more information see Section 17.2.5.4, “Replication Channel Based Filters”.

RESET SLAVE causes an implicit commit of an ongoing transaction. See Section 13.3.3, “Statements That Cause an Implicit Commit”.

If the slave SQL thread was in the middle of replicating temporary tables when it was stopped, and RESET SLAVE is issued, these replicated temporary tables are deleted on the slave.

RESET SLAVE does not reset the heartbeat period (Slave_heartbeat_period) or SSL_VERIFY_SERVER_CERT.

Note

When used on an NDB Cluster replication slave SQL node, RESET SLAVE clears the mysql.ndb_apply_status table. You should keep in mind when using this statement that ndb_apply_status uses the NDB storage engine and so is shared by all SQL nodes attached to the slave cluster.

You can override this behavior by issuing SET GLOBAL @@ndb_clear_apply_status=OFF prior to executing RESET SLAVE, which keeps the slave from purging the ndb_apply_status table in such cases.