Amazon ElastiCache for Redis has introduced removal of shards and dynamic addition while at the same time continuing to serve workloads

Amazon ElasticCache for Redis has introduced Online Cluster resizing to remove and add shards from an operating cluster. In the Redis Cluster workloads, the users can now dynamically scale out or scale in to adapt to changes in demand. When the Cluster continues to stay online and serve request the ElastiCache will resize the cluster and can redistribute hash slots consistently across the new shard configuration. You can also rebalance the cluster and evenly distribute the slot space without any necessity of changing the number of shards for optimized processing.