Issue
You are wondering if your app will experience downtime during the maintenance.
Resolution
Any maintenance requires some downtime. If you are on an high-availability (HA) plan, you are already aware of this downtime as you have taken steps to protect yourself in the event of an outage. If you are not on an HA plan, we are taking steps to ensure minimal downtime for your application. HA plans will experience some time after a maintenance where HA is unavailable while a new HA follower is created and caught up.
When the maintenance is triggered, the Primary Redis fails over to the Standby Redis. Your total downtime depends on your applications ability to recover from that failover. This downtime, for most customers, is measured in a handful of minutes.