MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4
The current progress of the replication applier (SQL) thread when
using row-based replication is monitored through Performance
Schema instrument stages, enabling you to track the processing of
operations and check the amount of work completed and work
estimated. When these Performance Schema instrument stages are
enabled the events_stages_current
table shows stages for applier threads and their progress. For
background information, see
Section 29.12.5, “Performance Schema Stage Event Tables”.
To track progress of all three row-based replication event types (write, update, delete):
Enable the three Performance Schema stages by issuing:
mysql>UPDATE performance_schema.setup_instruments SET ENABLED = 'YES'->WHERE NAME LIKE 'stage/sql/Applying batch of row changes%';
Wait for some events to be processed by the replication
applier thread and then check progress by looking into the
events_stages_current table. For
example to get progress for update events
issue:
mysql>SELECT WORK_COMPLETED, WORK_ESTIMATED FROM performance_schema.events_stages_current->WHERE EVENT_NAME LIKE 'stage/sql/Applying batch of row changes (update)'
If
binlog_rows_query_log_events
is enabled, information about queries is stored in the binary
log and is exposed in the processlist_info
field. To see the original query that triggered this event:
mysql>SELECT db, processlist_state, processlist_info FROM performance_schema.threads->WHERE processlist_state LIKE 'stage/sql/Applying batch of row changes%' AND thread_id = N;