8.14.7 Replication Replica SQL Thread States
The following list shows the most common states you may see in the State column for a replica server SQL thread:
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Making temporary file (append) before replaying LOAD DATA INFILEThe thread is executing a
LOAD DATAstatement 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 INFILEThe thread is executing a
LOAD DATAstatement and is creating a temporary file containing the data from which the replica reads rows. This state can only be encountered if the originalLOAD DATAstatement was logged by a source running a version of MySQL lower than MySQL 5.0.3. -
Reading event from the relay logThe thread has read an event from the relay log so that the event can be processed.
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Slave has read all relay log; waiting for more updatesThe 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.
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Waiting for an event from CoordinatorUsing the multithreaded replica (
slave_parallel_workersis greater than 1), one of the replica worker threads is waiting for an event from the coordinator thread. -
Waiting for slave mutex on exitA very brief state that occurs as the thread is stopping.
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Waiting for Slave Workers to free pending eventsThis waiting action occurs when the total size of events being processed by Workers exceeds the size of the
slave_pending_jobs_size_maxsystem variable. The Coordinator resumes scheduling when the size drops below this limit. This state occurs only whenslave_parallel_workersis set greater than 0. -
Waiting for the next event in relay logThe initial state before
Reading event from the relay log. -
Waiting until MASTER_DELAY seconds after master executed eventThe SQL thread has read an event but is waiting for the replica delay to lapse. This delay is set with the
MASTER_DELAYoption ofCHANGE MASTER TO.
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.
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