Amazon ElastiCache managed maintenance and service updates help page

Overview

We frequently upgrade our Amazon ElastiCache fleet, with patches and upgrades being applied to instances seamlessly. We do this in one of the two ways:

(a) continuous managed maintenance, and (b) service updates. These maintenance and service updates are required to apply upgrades that strengthen security, reliability, and operational performance.

Continuous managed maintenance happens from time to time and directly in your maintenance windows without requiring any action from your end.
Service updates give you flexibility to apply them on your own. They are timed and may be moved into the maintenance window to be applied by us after their due date lapses.

You have the option to manage updates yourself at any time prior to the scheduled maintenance window. When you manage an update yourself, your instance will receive the OS update when you relaunch the node and your scheduled maintenance window will be cancelled.

Service Updates

Continuous Managed Maintenance Updates