@dsloan-ethra So just to recap what was done here to adjust Debian 9 (where the referenced article also implies it is an issue for any Debian variant like Ubuntu) for others that might find the thread:
Edit /etc/mysql/mysql.conf.d/mysqld.cnf
vi /etc/mysql/mysql.conf.d/mysqld.cnf
Insert the following line in the
[mysqld] section
max_connections = 8000
Copy the systemd service descriptor file so you can customize it
cp /lib/systemd/system/mysql.service /etc/systemd/system/
Append the following lines to this file: /etc/systemd/system/mysql.service
LimitNOFILE=infinity
LimitMEMLOCK=infinity
Reload systemd processor
systemctl daemon-reload
Reload the mysql service
systemctl restart mysqld
Login to mysql as root and run the following command.
mysql> show variables like 'max_connections';
The response should be something like
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 8000 |
+-----------------+-------+
1 row in set (0.01 sec)
Done.
These are not my words, only restated from the accepted solution here that Sebastian found and referenced: https://www.rfc3092.net/2017/06/mysql-max_connections-limited-to-214-on-ubuntu-foo/