MySQL in a Nutshell

Name

START SLAVE

Synopsis

START SLAVE [IO_THREAD|SQL_THREAD]

START SLAVE [SQL_THREAD] 
   UNTIL MASTER_LOG_FILE = 'filename', MASTER_LOG_POS = position
START SLAVE [SQL_THREAD] 
   UNTIL RELAY_LOG_FILE = 'filename', RELAY_LOG_POS = position

Use this statement to start a slave server. In the first syntax structure shown, you can start the slave with the I/O thread or just with the SQL thread by using the respective keyword. You can start both by listing both keywords, separated by a comma. The default is to start both. The I/O thread will cause the slave to read SQL queries from the master server and to record them in the relay logfile. The SQL thread will read the relay logfile and then execute the SQL statements.

The second syntax structure is used to limit the reading of the threads to a specific point (given with MASTER_LOG_POS) in the master logfile (named with the MASTER_LOG_FILE parameter). With the UNTIL clause, processing of the logfiles given will stop when the position given is reached. The third syntax structure is used to specify the relay log file and to limit the reading of it. If the SQL_THREAD keyword is given in either of these latter two syntax structures, the reading will be limited to the SQL thread.

The starting of a slave thread isn’t always dependable. Run the SHOW SLAVE STATUS statement to confirm that the thread began and remained running.