- 12.5.2 SQL Statements for Controlling Slave Servers
- 12.5.2.1 CHANGE MASTER TO Syntax
- 12.5.2.2 LOAD DATA FROM MASTER Syntax
- 12.5.2.3 LOAD TABLE tbl_name FROM MASTER Syntax
- 12.5.2.4 MASTER_POS_WAIT() Syntax
- 12.5.2.5 RESET SLAVE Syntax
- 12.5.2.6 SET GLOBAL sql_slave_skip_counter Syntax
- 12.5.2.7 START SLAVE Syntax
- 12.5.2.8 STOP SLAVE Syntax
SET GLOBAL sql_slave_skip_counter = N
This statement skips the next N
events from the master. This is useful for recovering from
replication stops caused by a statement.
This statement is valid only when the slave threads are not running. Otherwise, it produces an error.
When using this statement, it is important to understand that the binary log is actually organized as a sequence of groups known as event groups. Each event group consists of a sequence of events.
For transactional tables, an event group corresponds to a transaction.
For nontransactional tables, an event group corresponds to a single SQL statement.
Note
A single transaction can contain changes to both transactional and nontransactional tables.
When you use SET GLOBAL
sql_slave_skip_counter to skip events and the result
is in the middle of a group, the slave continues to skip events
until it reaches the end of the group. Execution then starts
with the next event group.
User Comments
Setting this variable isn't like setting other server variables: you can't read the variable back again as @@sql_slave_skip_counter, and it isn't really a "global variable." Rather, it's a variable that only the slave thread reads.
When you restart the slave threads again with START SLAVE, the slave skips statements and decrements the variable until it reaches 0, at which point it begins executing statements again. You can watch this happening by executing SHOW SLAVE STATUS, where the variable's value appears in the Skip_Counter column. This is the only place you can see its value.
The effect is that the setting isn't persistent. If you set it to 1, start the slave, and the slave has an error in replication sometime later, the variable won't still be set to 1. It'll be 0. At that point, if you want the slave to skip the statement that caused the error, you'll have to set it to 1 again.
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