Information Schema INNODB_MUTEXES Table
The INNODB_MUTEXES table monitors mutex and rw locks waits. It has the following columns:
| Column | Description |
|---|---|
NAME | Name of the lock, as it appears in the source code. |
CREATE_FILE | File name of the mutex implementation. |
CREATE_LINE | Line number of the mutex implementation. |
OS_WAITS | How many times the mutex occurred. |
The CREATE_FILE and CREATE_LINE columns depend on the InnoDB/XtraDB version.
Note that since MariaDB 10.2.2, the table has only been providing information about
rw_lock_t, not any mutexes. From MariaDB 10.2.2 until MariaDB 10.2.32, MariaDB 10.3.23, MariaDB 10.4.13 and MariaDB 10.5.1, the NAME column was not populated (MDEV-21636).
The SHOW ENGINE INNODB STATUS statement provides similar information.
Examples
SELECT * FROM INNODB_MUTEXES; +------------------------------+---------------------+-------------+----------+ | NAME | CREATE_FILE | CREATE_LINE | OS_WAITS | +------------------------------+---------------------+-------------+----------+ | &dict_sys->mutex | dict0dict.cc | 989 | 2 | | &buf_pool->flush_state_mutex | buf0buf.cc | 1388 | 1 | | &log_sys->checkpoint_lock | log0log.cc | 1014 | 2 | | &block->lock | combined buf0buf.cc | 1120 | 1 | +------------------------------+---------------------+-------------+----------+
Content reproduced on this site is the property of its respective owners,
and this content is not reviewed in advance by MariaDB. The views, information and opinions
expressed by this content do not necessarily represent those of MariaDB or any other party.
