This page is original PmaControl documentation. It keeps a practical index structure for MySQL optimization work, without copying third-party content or depending on an external product.
Role
Number of threads that clean dirty pages.
Diagnosis
SHOW VARIABLES LIKE 'innodb_page_cleaners';
SHOW GLOBAL STATUS LIKE '%innodb%';
The status counters do not always use the same name as the variable. Use this command as a starting point, then complete with performance_schema, SHOW ENGINE INNODB STATUS, or system metrics.
Tuning
Must stay consistent with buffer pool instances and I/O capacity.
Risks
- A global value that is too high can increase memory consumed at startup.
- A per-connection value can explode with
max_connections. - A change must be tested with a before/after measurement and rollback.