25.12.2.1 The setup_actors Table

The setup_actors table contains information that determines whether to enable monitoring and historical event logging for new foreground server threads (threads associated with client connections). This table has a maximum size of 100 rows by default. To change the table size, modify the performance_schema_setup_actors_size system variable at server startup.

For each new foreground thread, the Performance Schema matches the user and host for the thread against the rows of the setup_actors table. If a row from that table matches, its ENABLED and HISTORY column values are used to set the INSTRUMENTED and HISTORY columns, respectively, of the threads table row for the thread. This enables instrumenting and historical event logging to be applied selectively per host, user, or account (user and host combination). If there is no match, the INSTRUMENTED and HISTORY columns for the thread are set to NO.

For background threads, there is no associated user. INSTRUMENTED and HISTORY are YES by default and setup_actors is not consulted.

The initial contents of the setup_actors table match any user and host combination, so monitoring and historical event collection are enabled by default for all foreground threads:

mysql> SELECT * FROM performance_schema.setup_actors;
+------+------+------+---------+---------+
| HOST | USER | ROLE | ENABLED | HISTORY |
+------+------+------+---------+---------+
| %    | %    | %    | YES     | YES     |
+------+------+------+---------+---------+

For information about how to use the setup_actors table to affect event monitoring, see Section 25.4.6, “Pre-Filtering by Thread”.

Modifications to the setup_actors table affect only foreground threads created subsequent to the modification, not existing threads. To affect existing threads, modify the INSTRUMENTED and HISTORY columns of threads table rows.

The setup_actors table has these columns:

• HOST

  The host name. This should be a literal name, or '%' to mean “any host.”

• USER

  The user name. This should be a literal name, or '%' to mean “any user.”

• ROLE

  Unused.

• ENABLED

  Whether to enable instrumentation for foreground threads matched by the row. The value is YES or NO.

• HISTORY

  Whether to log historical events for foreground threads matched by the row. The value is YES or NO.

TRUNCATE TABLE is permitted for the setup_actors table. It removes the rows.