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.
Reading
Latency measures the query response time perceived by clients. It increases with locks, I/O, inefficient plans, CPU contention, or a saturated connection queue.
Useful Measurements
SHOW GLOBAL STATUS LIKE 'Questions';
SHOW GLOBAL STATUS LIKE 'Threads_running';
SHOW GLOBAL STATUS LIKE 'Slow_queries';
SHOW GLOBAL STATUS LIKE 'Aborted_clients';
Diagnosis
Always compare the metric with application load and time. An isolated counter is not enough: the per-minute delta and correlation with incidents provide the usable signal.
Possible Actions
- Identify the responsible queries or connections.
- Check MySQL and system limits.
- Test a targeted correction, then measure the same metric after the change.