In every application there is a configuration file which requires the setting of some essential parameters, such as
$dbhost = "62.149.150.XX";
$dbname = "databasename";
$dbuser = "yourusername";
$dbpasswd = "yourpassword";
As far as $dbhost is concerned, according to the db location, enter the IP address corresponding to the second mysql server 18.104.22.168 or 22.214.171.124 etc
You can find this information in the email for the activation of the service .
Attention not to enter spaces in the configuration strings.
For further information you can consult the mysql guide on the vademecum, starting from here.