Posted On: Nov 23, 2021

You can now use data tiering for Amazon ElastiCache for Redis as a lower cost way to scale your clusters to up to hundreds of terabytes of capacity. Data tiering provides a new price-performance option for Redis workloads by utilizing lower-cost solid state drives (SSDs) in each cluster node in addition to storing data in memory. It is ideal for workloads that access up to 20% of their overall dataset regularly, and for applications that can tolerate additional latency when accessing data on SSD.

When using clusters with data tiering, ElastiCache is designed to automatically and transparently move the least recently used items from memory to locally attached NVMe SSDs when available memory capacity is completely consumed. When an item that moves to SSD is subsequently accessed, ElastiCache moves it back to memory asynchronously before serving the request. Assuming 500-byte String values, you can expect an additional 300µs latency on average for requests to data stored on SSD compared to requests to data in memory.

ElastiCache data tiering is available when using Redis version 6.2 and above on Graviton2-based R6gd nodes. R6gd nodes have nearly 5x more total capacity (memory + SSD) and can help you achieve over 60% savings when running at maximum utilization compared to R6g nodes (memory only).

To get started using ElastiCache data tiering, create a new cluster using one of the R6gd node types using the AWS Management Console for ElastiCache, the AWS CLI, or one of the SDKs. Data tiering on R6gd nodes is available in the Asia Pacific (Singapore), Asia Pacific (Sydney), Asia Pacific (Tokyo), Europe (Frankfurt), Europe (Ireland), US East (N. Virginia), US East (Ohio), US West (N. California), and US West (Oregon) Regions. For pricing, see Amazon ElastiCache pricing and for more information, see the ElastiCache data tiering documentation.