Help me trubleshooting Mysql High CPU

Hello Guys,

I’m running few websites on my droplet (8G, 4vcpu) and one of my websites causing extremely high CPU usage (it has only a few simultaneaus visitor). MySql is guilty, accoring to htop. When I turn off this website, everything goes back to normal. I have tried everything to identify the issue, but it comes back time-to-time (sometimes it is good for weeks, then the high CPU load comes back. High = 100% always, according to the DO draphs.)

I have tried SHOW PROCESSLIST; but I cant see too much connections, or slow queries (basically the site is fast, most of the times, but not always!) i have tried to play with my.cnf, one of my friends fine-tuned it, then it was good for few weeks, then since a few days the graph touched the ceiling again.

I’m using cloudflare and a bit suspicious that It I see very high bandwidth usage and high Traffic (users, crawler bots, threats included) (High = compared to my other sites which has much more traffic (measured by Google Analytics). I cant see uncommon number in the number of threats. I’ve tried to turn on the Cloudflare “im under attack” mode, but the cpu usage is the same.

Any suggestions ? should I copy my.cnf here ? I have a feeling that I will find the answer somewhere else.

Thank you guys for the help !!!