13.4.1.2 RESET MASTER Syntax

RESET MASTER enables you to delete any binary log files and their related binary log index file, returning the master to its state before binary logging was started.

Issuing RESET MASTER without the optional TO clause deletes all binary log files listed in the index file, resets the binary log index file to be empty, and creates a new binary log file starting at 1. Use the optional TO clause to start the binary log file index from a number other than 1 after the reset. Issuing RESET MASTER also clears the values of the gtid_purged system variable and the gtid_executed system variable; that is, issuing this statement sets each of these values to an empty string (''). This statement also clears the mysql.gtid_executed table (see mysql.gtid_executed Table).

Using RESET MASTER with the TO clause to specify a binary log file index number to start from simplifies failover by providing a single statement alternative to the FLUSH BINARY LOGS and PURGE BINARY LOGS TO statements. Check that you are using a reasonable value for the index number. If you enter an incorrect value, you can correct this by issuing another RESET MASTER statement with or without the TO clause. If you do not correct a value that is out of range, the server cannot be restarted.

The following example demonstrates TO clause usage:

RESET MASTER without the TO clause can prove useful when you first set up the master and the slave, so that you can verify the setup as follows:

After verifying the setup, resetting the master and slave and ensuring that no unwanted data or binary log files generated by testing remain on the master or slave, you can start the slave and begin replicating.