8.12.5.6. Replication Slave SQL Thread States

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 log

The initial state before Reading event from the relay log.
Reading event from the relay log

The thread has read an event from the relay log so that the event can be processed.
Making temp file

The thread is executing a LOAD DATA INFILE statement 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 it

The 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 exit

A very brief state that occurs as the thread is stopping.
Waiting until MASTER_DELAY seconds after master executed event

The SQL thread has read an event but is waiting for the slave delay to lapse. This delay is set with the MASTER_DELAY option of CHANGE MASTER TO.

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.