These thread states occur on a replica server but are associated with connection threads, not with the I/O or SQL threads.

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.