Thanks James for the quick response! I have already tried to add there the parameters but seems not to take effect in anyway.
Here I follow some steps from this simple guide, that semmed correct https://www.fromdual.com/node/1278
cat /proc/pidof mysqld
/limits | egrep 'Limit|open files' I get the current values, and are always fixed to 16364, even if I try to set them to 50000.
The dir /etc/security/limits.d its empty (my Ubuntu 16.04 server is fresh newly installed)
And the file /etc/security/limits.conf its by default with everyline commented, so here I added this (just to test) but seems it has no effect. Tried several alternatives
mysql soft nofile 50000
mariadb soft nofile 50000
frappe soft nofile 50000
frappe hard nofile 50000
mysqld soft nofile 50000
mysqld hard nofile 50000
I might need to look for help in a Ubuntuer forum, I know, but… is it normal the warning message? do you have it also?
I am sure I did not change any special config, just clean installed Ubuntu and playbook script.