The max number of simultaneous connections to your MySQL database is 20. This normally is not a problem because MySQL connections are made and destroyed within a fraction of a second. If you are getting a max_user_connections error:
- Your code is opening the connection to the database, but not closing it. Please see the following link for more help with properly opening and closing your database connections –http://w3schools.com/php/php_mysql_connect.asp
- Your software is configured to use pconnect / Persistent Connections. Please read the documentation for your software to find out how to disable pconnect.
Most of the time, the problem is due to the second scenario, using pconnect, because most php applications being ran on the server are open source projects rather then custom code that users have written.