I have an ElastiCache Redis (cluster mode disabled) Cluster and would like to change to an ElastiCache Redis (cluster mode enabled) Cluster. I haven't found a way to do this, but also have not found a statement that it is not possible either. This is complicated by the confusing language around 'cluster' and 'cluster mode'.
This document from Amazon states that:
Currently, Redis (cluster mode enabled) does not support creating a cluster with replicas using an available single-node cluster.
This somewhat implies that it can be done from a cluster with multiple nodes.
Similarly, this document about modifying a cluster says:
You can modify a Redis (cluster mode disabled) cluster's settings using the ElastiCache console, the AWS CLI, or the ElastiCache API. Currently, ElastiCache does not support modifying a Redis (cluster mode enabled) replication group except by creating a backup of the current replication group then using that backup to seed a new Redis (cluster mode enabled) replication group.
Again, this implies that you can change a Redis (cluster mode disabled) cluster but doesn't really say one way or another. Though, I get the idea from this statement that I'd need to back up the current Redis (cluster mode disabled) cluster and then use that to seed a new Redis (cluster mode enabled) cluster.