The max number of simultaneous connections from a database user to a MySQL database is set to 30 on our servers. This generally is not an issue as MySQL connections rarely last for longer than a fraction of a second, so having thirty open at once is rare. If you are getting a max_user_connections error:

• Your code is opening the connection to the database, but not closing it. Here is an article with more information about closing your database connections.
• Your software is configured to use pconnect or Persistent Connections. Please consult your documentation to find out how to disable pconnect.

Most of the time the problem is due to the second scenario (using pconnect), so be sure to check your documentation to prevent getting max_user_connections errors.

It's important to note that max_user_connections and max_connections are not the same thing. While max_user_connections is the maximum number of connections to a database from a database user, max_connections is server wide setting.