Amazon ElastiCache for Redis data tiering on Graviton2-based R6gd nodes now supports auto scaling to automatically adjust capacity to maintain steady and predictable performance at the lowest possible cost. You can automatically scale your cluster horizontally by adding or removing shards or replica nodes. ElastiCache for Redis data tiering uses AWS Application Auto Scaling to manage scaling and Amazon CloudWatch metrics to determine when it is time to scale up or down.
Source:: Amazon AWS