13.4.2.6 STOP SLAVE Statement

STOP SLAVE [thread_types] [channel_option]

thread_types:
    [thread_type [, thread_type] ... ]

thread_type: IO_THREAD | SQL_THREAD

channel_option:
    FOR CHANNEL channel

Stops the replication threads. STOP SLAVE requires the SUPER privilege. Recommended best practice is to execute STOP SLAVE on the replica before stopping the replica server (see Section 5.1.16, “The Server Shutdown Process”, for more information).

When using the row-based logging format: You should execute STOP SLAVE or STOP SLAVE SQL_THREAD on the replica prior to shutting down the replica server if you are replicating any tables that use a nontransactional storage engine (see the Note later in this section).

Like START SLAVE, this statement may be used with the IO_THREAD and SQL_THREAD options to name the thread or threads to be stopped. Note that the Group Replication applier channel (group_replication_applier) has no replication I/O thread, only a replication SQL thread. Using the SQL_THREAD option therefore stops this channel completely.

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

gtid_next must be set to AUTOMATIC before issuing this statement.

You can control how long STOP SLAVE waits before timing out by setting the rpl_stop_slave_timeout system variable. This can be used to avoid deadlocks between STOP SLAVE and other SQL statements using different client connections to the replica. When the timeout value is reached, the issuing client returns an error message and stops waiting, but the STOP SLAVE instruction remains in effect. Once the replication threads are no longer busy, the STOP SLAVE statement is executed and the replica stops.

Some CHANGE MASTER TO statements are allowed while the replica is running, depending on the states of the replication SQL thread and the replication I/O thread. However, using STOP SLAVE prior to executing CHANGE MASTER TO in such cases is still supported. See Section 13.4.2.1, “CHANGE MASTER TO Statement”, and Section 16.3.7, “Switching Sources During Failover”, for more information.

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 STOP SLAVE statement to a specific replication channel. If no channel is named and no extra channels exist, the statement applies to the default channel. If a STOP SLAVE statement does not name a channel when using multiple channels, this statement stops the specified threads for all channels. This statement cannot be used with the group_replication_recovery channel. See Section 16.2.2, “Replication Channels” for more information.

When using statement-based replication: changing the source while it has open temporary tables is potentially unsafe. This is one of the reasons why statement-based replication of temporary tables is not recommended. You can find out whether there are any temporary tables on the replica by checking the value of Slave_open_temp_tables; when using statement-based replication, this value should be 0 before executing CHANGE MASTER TO. If there are any temporary tables open on the replica, issuing a CHANGE MASTER TO statement after issuing a STOP SLAVE causes an ER_WARN_OPEN_TEMP_TABLES_MUST_BE_ZERO warning.

When using a multithreaded replica (slave_parallel_workers is a nonzero value), any gaps in the sequence of transactions executed from the relay log are closed as part of stopping the worker threads. If the replica is stopped unexpectedly (for example due to an error in a worker thread, or another thread issuing KILL) while a STOP SLAVE statement is executing, the sequence of executed transactions from the relay log may become inconsistent. See Section 16.4.1.32, “Replication and Transaction Inconsistencies”, for more information.

If the current replication event group has modified one or more nontransactional tables, STOP SLAVE waits for up to 60 seconds for the event group to complete, unless you issue a KILL QUERY or KILL CONNECTION statement for the replication SQL thread. If the event group remains incomplete after the timeout, an error message is logged.