7.5.6.2 MLE Component Status and Session Information

Once the MLE component is installed, you can obtain information about the component as shown here:

mysql> SHOW STATUS LIKE 'mle%';
+-------------------------+---------------+
| Variable_name           | Value         |
+-------------------------+---------------+
| mle_heap_status         | Not Allocated |
| mle_languages_supported | JavaScript    |
| mle_memory_used         | 0             |
| mle_status              | Inactive      |
+-------------------------+---------------+
4 rows in set (0.01 sec)

As with other MySQL status variables, you can also access those shown here by selecting from the Performance Schema global_status table.

The MLE component's status is indicated by the Mle_status status variable. This remains Inactive until a user creates or invokes a stored procedure or function using a language supported by MLE, at which time it becomes (very briefly) Initializing or (more usually) Active. It remains Active until the server is shutting down or restarting, at which the value is Pending shutdown.

You can obtain status information and console output from an MLE stored program using the loadable function mle_session_state() supplied by the MLE component. See the description of this function for more information.

Mle_languages_supported shows a list of languages supported by this instance of the component; in MySQL 9.0, this is always JavaScript.

See Section 7.5.6.3, “MLE Component Memory and Thread Usage”, for information about status variables relating to MLE component memory usage.

You can also obtain information about MLE sessions from system status variables. The Mle_sessions status variable provides the number of active MLE sessions. Mle_sessions_max displays the greatest number of MLE sessions simultaneously active at any one time since the MLE component became active. Mle_session_resets shows the number of times the session state was cleared by calling mle_session_reset(). See the descriptions of these status variables for more information.