A common scenario among customers is stopping the SQL server to apply hot fixes or security updates. During this time ARS will report that the database is not available and clients will not be able to connect via the MMC or web interface.
Active Roles automatically attempts to reconnect to SQL every 10 minutes. Therefore, one maintenance is complete on the SQL server, Active Roles will connect within 10 minutes and clients will be able to reconnect shortly after Active Roles starts. You may also restart the Active Roles service to force it.