I have a VPS Web server (Apache 2.4/PHP 7.x + Varnish 4.1) running with Percona 5.6. I have 20 Gb of RAM. I serve Wordpress sites mainly all using innodb.
So I´m thinking of ways of improving MySQL performance and of course for that, you need to measure.
Currently I´m checking, there are no slow queries and read and writes perform well. I have enabled slow queries logging but the truth is that most queries logged are not slow, they are just slow when the web server load is too high, so when you try to check those queries at other time, there isn´t anything wrong with them.
So I migrated from Percona 5.5 to 5.6 and enabled query cache. I´ve heard you can use memcached for caching reads and writes but not sure about this.
So I started to look into graphical open source tools to measure my server (mostly MySQL) performance before doing any change.
Sincerely, I´m overwhelmed on the possibilities, kibana, grafana, etc and I don´t know which one to choose.
For starters I was thinking of setting up a virtual machine on my laptop and configure one of those and get the data from the server (not sure if this is feasible without loosing information when the VM is not running).
What do you guys recommend me?