I have found the following for: https://pteropaste.com/7c87/
@calm gorge; Your database has reached the limit of maximum concurrent connections (150). You can increase the limit to 300 (or any number) by adding the following text to the bottom of your my.cnf file
[mysqld]
max_connections=300
Type find /etc -iname my.cnf to find the location of the file. Restart your mysql systemctl restart mysql to apply the changes and voilà!