DB failover settings in .env file?

Did some testing today and sadly it doesn't seem to work. The browser spins for a few seconds and then says "Connection timed out" instead of looking for the failover connection. 

Here's what I've got:

Code:

database.default.hostname = primaryserver.com
database.default.database = mydatabse
database.default.username = myuser
database.default.password = mypass
database.default.DBDriver = MySQLi

database.default.failover.hostname = secondaryserver.com
database.default.failover.database = mydatabase
database.default.failover.username = myuser
database.default.failover.password = mypass
database.default.failover.DBDriver = MySQLi

Any ideas?

Designer, developer and Diet Dr. Pepper addict. Messing up PHP since <?= $when['year';] ?>