Horizontal scaling in Amazon ElastiCache involves increasing the number of cache nodes to handle more requests or data. This is often referred to as sharding, and it allows for linear scalability by distributing data across multiple nodes.
In ElastiCache, you have two primary options for implementing horizontal scaling:
Here's an example using the AWS CLI:
This command would scale out a replication group named "my-replication-group" to six cache clusters.
Remember to monitor performance after scaling to ensure that your new configuration adequately handles your workload. In addition, be aware that while horizontal scaling can increase capacity and throughput, it may also introduce latency due to network overhead between nodes, so consider this when planning your scaling strategy.