The following list shows the most common states you may see in
the State column for a slave server SQL
thread:
Waiting for the next event in relay logThe initial state before
Reading event from the relay log.Reading event from the relay logThe thread has read an event from the relay log so that the event can be processed.
The thread is executing a
LOAD DATA INFILEstatement and is creating a temporary file containing the data from which the slave will read rows.Slave has read all relay log; waiting for the slave I/O thread to update itThe thread has processed all events in the relay log files, and is now waiting for the I/O thread to write new events to the relay log.
Waiting for slave mutex on exitA very brief state that occurs as the thread is stopping.
The State column for the I/O thread may
also show the text of a statement. This indicates that the
thread has read an event from the relay log, extracted the
statement from it, and is executing it.