Amazon ElastiCache for Redis
ElastiCache for Redis User Guide (API Version 2015-02-02)

Determine Requirements

Before you create a Redis cluster or replication group, you should always determine the requirements for the cluster or replication group so that when you create it, it will meet your business needs and not need to be redone. Because in this exercise we will largely accept default values for the cluster, we will dispense with determining requirements. For more information, see Determine Your Requirements.