Too many connections error in MySQL

The too many connections error appears when attempting to connect to a
server and the available connections, set to 100 by default, are in use
already.

Keep in mind that MySQL® has a variable max_connections +1 for client connections,
the +1 is dedicated for accounts with CONNECTION_ADMIN privileges.

Solution

Perform the following steps to fix this issue:

1. Identify the max_connections variable value:

   mysql --user="root" --password="PASSWORD" --execute='SHOW VARIABLES LIKE "max_connections";

   The output looks like this:

   Variable_name	Value
   max_connections	100

2. Use your favorite text editor to change /etc/mysql/my.cnf and set
   the following values:

   max_connections = 500

   max_user_connections = 500

   Note: Increasing the amount of possible connections directly affects the
   amount of RAM consumed.

   The command mysql --help can help locate the my.cnf file because it displays
   default options on the following files:

   • /etc/my.cnf
   • /etc/mysql/my.cnf
   • /usr/local/etc/my.cnf
   • ~/.my.cnf

3. Restart the MySQL service and to apply the changes.