Very High CPU when we publish post in WordPress - MySQL spikes CPU
Whenever we upload & publish news, the server load will spike. and When 2 or 3 of them upload news at the same time, the server will hang for a few minutes (Internal Server Error) and then back to normal again.
Every time I publish or update a post in Wordpress there is a huge CPU spike due to MYSQL
I have deactivated plugins and themes, and the problem persists.
Every thing else on the site is very fast when there is high traffic. We tried increasing the server no luck.
Any help would be greatly appreciated!
Ubuntu 16.04.1 x64
Size: 6 vCPUs
16GB / 160GB Disk