As tables increase in size and more and more users come online, it becomes necessary to fine-tune the database server from time to time. The secret to knowing what adjustments to make is to perform regular monitoring. Most databases offer dozens, if not hundreds, of performance metrics that one can assess.
As a database administrator, the top priority is to keep the databases and dependent applications running well at all times. The best weapon is the careful monitoring of key performance metrics. In a perfect world, one would want to be up-to-date regarding every aspect of the activity of the database. One would want to know how many events occurred, how big they were, when they happened, and how long they took to complete.
There is no shortage of tools that can monitor resource consumption, provide instantaneous status snapshots, and generate wait analysis and graphs. The challenge is that some metrics can be expensive to measure, and perhaps they can require much work to analyze.
Read the whitepaper “Top metrics to monitor in MySQL databases” by Shree Nair to learn more about how to monitor key performance metrics.