Information Schema THREAD_POOL_GROUPS Table

MariaDB starting with 10.5

The Information Schema THREAD_POOL_GROUPS table was introduced in MariaDB 10.5.0.

The table provides information about thread pool groups, and contains the following columns:

Column	Description
Column	Description
GROUP_ID	the thread group this row is showing data for
CONNECTIONS	the number of clients currently connected to this thread group
THREADS	total number of threads in this group (ACTIVE+STANDBY+LISTENER)
ACTIVE_THREADS	number of threads currently executing a query
STANDBY_THREADS	number of threads in reserve that do not currently execute anything
QUEUE_LENGTH	number of client requests waiting for execution
HAS_LISTENER	whether there is an active listener thread right now, always 1 if thread_pool_dedicated_listener is ON
IS_STALLED	whether there's currently an active worker thread in this group that has exceeded thread_pool_stall_limit time

Setting thread_pool_dedicated_listener will give each group its own dedicated listener, and the listener thread will not pick up work items. As a result, the actual queue size in the table will be more exact, since IO requests are immediately dequeued from poll, without delay.

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