Issue
You are wondering if you need to perform anything to do the Heroku Redis maintenance.
Resolution
There are three different ways for maintenance to occur. The most common way is to do let Heroku perform the maintenance for you. We use your databases maintenance window to determine the best time to run this maintenance automatically.
The following two methods are triggered manually by you.
If you wish to run your maintenance manually you can do so in one of two ways. The first method is via heroku redis:maintenance --run --force. This immediately fails over to your HA Standby or the hidden Standby if it is caught up. Your application immediately restarts and is pointed to the new Primary (former Standby). The impact for this option would be similar to the case where Heroku performs the maintenance for you.
The other method involves putting your application into maintenance mode before performing the failover. This method can have benefits such as providing a clean landing page for your users, but total downtime can be longer as it is a manual process to enable and disable maintenance mode. We have more detailed information on the maintenance mode page.