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

Increasing Read Capacity

To increase read capacity, add read replicas (up to a maximum of five) to your Redis replication group.

You can scale your Redis cluster’s read capacity using the ElastiCache console, the AWS CLI, or the ElastiCache API. For more information, see Adding a Read Replica, for Redis (cluster mode disabled) Replication Groups.