Maintenance Window

Every cache cluster has a weekly maintenance window during which any system changes are applied. If you don't specify a preferred maintenance window when you create the cache cluster, ElastiCache assigns a 30-minute maintenance window on a randomly selected day of the week.

The 30-minute maintenance window is selected at random from an 8-hour block of time per region. The following table lists the time blocks for each Region from which the default maintenance windows are assigned.

The maintenance window should fall at the time of lowest usage and thus might need modification from time to time. You can specify a time range of up to 24 hours in duration during which any maintenance activities you have requested should occur. For example, if you enable Auto Minor Version Upgrades for your cache cluster, non-critical Memcache software updates are applied during this time. Such updates occur infrequently (generally once every few months) and will be announced on the AWS ElastiCache forum two weeks prior to being applied. Any deferred or pending cache cluster modifications you have requested would also occur during this time.

For more information on how to adjust the preferred maintenance window for your cache clusters, see Adjusting the Preferred Maintenance Window.