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Information Schema INNODB_MUTEXES Table

MariaDB starting with 10.1.3

The Information Schema INNODB_MUTEXES table was added in MariaDB 10.1.3

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.

Remember that CREATE_FILE and CREATE_LINE depend on your InnoDB/XtraDB version.

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 |
+------------------------------+---------------------+-------------+----------+

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https://mariadb.com/kb/en/information-schema-innodb_mutexes-table/