MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

10.14.6 Replication SQL Thread States

The following list shows the most common states you may see in the State column for a replication SQL thread on a replica server.

In MySQL 8.0.26, incompatible changes were made to instrumentation names, including the names of thread stages, containing the terms master, which is changed to source, slave, which is changed to replica, and mts (for multithreaded slave), which is changed to mta (for multithreaded applier). Monitoring tools that work with these instrumentation names might be impacted. If the incompatible changes have an impact for you, set the terminology_use_previous system variable to BEFORE_8_0_26 to make MySQL Server use the old versions of the names for the objects specified in the previous list. This enables monitoring tools that rely on the old names to continue working until they can be updated to use the new names.

Set the terminology_use_previous system variable with session scope to support individual functions, or global scope to be a default for all new sessions. When global scope is used, the slow query log contains the old versions of the names.

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.