MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0
The following list shows the most common states you may see in
the State
column for a replication SQL thread
on a replica server:
Making temporary file (append) before replaying
LOAD DATA INFILE
The thread is executing a LOAD
DATA
statement and is appending the data to a
temporary file containing the data from which the replica
reads rows.
Making temporary file (create) before replaying
LOAD DATA INFILE
The thread is executing a LOAD
DATA
statement and is creating a temporary file
containing the data from which the replica reads rows. This
state can only be encountered if the original
LOAD DATA
statement was
logged by a source running a version of MySQL lower than
MySQL 5.0.3.
Reading event from the relay log
The thread has read an event from the relay log so that the event can be processed.
Slave has read all relay log; waiting for more
updates
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 an event from Coordinator
Using the multithreaded replica
(slave_parallel_workers
is
greater than 1), one of the replica worker threads is
waiting for an event from the coordinator thread.
Waiting for slave mutex on exit
A very brief state that occurs as the thread is stopping.
Waiting for Slave Workers to free pending
events
This waiting action occurs when the total size of events
being processed by Workers exceeds the size of the
slave_pending_jobs_size_max
system variable. The Coordinator resumes scheduling when the
size drops below this limit. This state occurs only when
slave_parallel_workers
is
set greater than 0.
Waiting for the next event in relay log
The initial state before Reading event from the
relay log
.
Waiting until MASTER_DELAY seconds after master
executed event
The SQL thread has read an event but is waiting for the
replica delay to lapse. This delay is set with the
SOURCE_DELAY
|
MASTER_DELAY
option of the
CHANGE REPLICATION SOURCE TO
statement (from MySQL 8.0.23) or CHANGE
MASTER TO
statement (before MySQL 8.0.23).
The Info
column for the SQL 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 may be executing it.