MySQL 9.0 Reference Manual Including MySQL NDB Cluster 9.0
For a multithreaded replica, the replica uses multiple worker
threads and a coordinator thread to manage them, and this
table shows the status of the coordinator thread. For a
single-threaded replica, this table is empty. For a
multithreaded replica, the
replication_applier_status_by_worker
table shows the status of the worker threads. This table
provides information about the last transaction which was
buffered by the coordinator thread to a worker’s queue, as
well as the transaction it is currently buffering. The start
timestamp refers to when this thread read the first event of
the transaction from the relay log to buffer it to a
worker’s queue, while the end timestamp refers to when the
last event finished buffering to the worker’s queue.
The
replication_applier_status_by_coordinator
table has these columns:
CHANNEL_NAME
The replication channel which this row is displaying. There is always a default replication channel, and more replication channels can be added. See Section 19.2.2, “Replication Channels” for more information.
THREAD_ID
The SQL/coordinator thread ID.
SERVICE_STATE
ON (thread exists and is active or
idle) or OFF (thread no longer exists).
LAST_ERROR_NUMBER,
LAST_ERROR_MESSAGE
The error number and error message of the most recent
error that caused the SQL/coordinator thread to stop. An
error number of 0 and message which is an empty string
means “no error”. If the
LAST_ERROR_MESSAGE value is not empty,
the error values also appear in the replica's error log.
Issuing RESET BINARY LOGS AND
GTIDS or
RESET
REPLICA resets the values shown in these
columns.
All error codes and messages displayed in the
LAST_ERROR_NUMBER and
LAST_ERROR_MESSAGE columns correspond
to error values listed in
Server Error Message Reference.
LAST_ERROR_TIMESTAMP
A timestamp in '
format that shows when the most recent SQL/coordinator
error occurred.
YYYY-MM-DD
hh:mm:ss[.fraction]'
LAST_PROCESSED_TRANSACTION
The global transaction ID (GTID) of the last transaction processed by this coordinator.
LAST_PROCESSED_TRANSACTION_ORIGINAL_COMMIT_TIMESTAMP
A timestamp in '
format that shows when the last transaction processed by
this coordinator was committed on the original source.
YYYY-MM-DD
hh:mm:ss[.fraction]'
LAST_PROCESSED_TRANSACTION_IMMEDIATE_COMMIT_TIMESTAMP
A timestamp in '
format that shows when the last transaction processed by
this coordinator was committed on the immediate source.
YYYY-MM-DD
hh:mm:ss[.fraction]'
LAST_PROCESSED_TRANSACTION_START_BUFFER_TIMESTAMP
A timestamp in '
format that shows when this coordinator thread started
writing the last transaction to the buffer of a worker
thread.
YYYY-MM-DD
hh:mm:ss[.fraction]'
LAST_PROCESSED_TRANSACTION_END_BUFFER_TIMESTAMP
A timestamp in '
format that shows when the last transaction was written to
the buffer of a worker thread by this coordinator thread.
YYYY-MM-DD
hh:mm:ss[.fraction]'
PROCESSING_TRANSACTION
The global transaction ID (GTID) of the transaction that this coordinator thread is currently processing.
PROCESSING_TRANSACTION_ORIGINAL_COMMIT_TIMESTAMP
A timestamp in '
format that shows when the currently processing
transaction was committed on the original source.
YYYY-MM-DD
hh:mm:ss[.fraction]'
PROCESSING_TRANSACTION_IMMEDIATE_COMMIT_TIMESTAMP
A timestamp in '
format that shows when the currently processing
transaction was committed on the immediate source.
YYYY-MM-DD
hh:mm:ss[.fraction]'
PROCESSING_TRANSACTION_START_BUFFER_TIMESTAMP
A timestamp in '
format that shows when this coordinator thread started
writing the currently processing transaction to the buffer
of a worker thread.
YYYY-MM-DD
hh:mm:ss[.fraction]'
When the Performance Schema is disabled, local timing information is not collected, so the fields showing the start and end timestamps for buffered transactions are zero.
The
replication_applier_status_by_coordinator
table has these indexes:
Primary key on (CHANNEL_NAME)
Index on (THREAD_ID)
The following table shows the correspondence between
replication_applier_status_by_coordinator
columns and
SHOW
REPLICA STATUS columns.
replication_applier_status_by_coordinator Column |
SHOW REPLICA STATUS Column |
|---|---|
THREAD_ID |
None |
SERVICE_STATE |
Replica_SQL_Running |
LAST_ERROR_NUMBER |
Last_SQL_Errno |
LAST_ERROR_MESSAGE |
Last_SQL_Error |
LAST_ERROR_TIMESTAMP |
Last_SQL_Error_Timestamp |