ElastiCache Enable Data Tiering

Opportunity Name: ElastiCache Enable Data Tiering

AWS Resource Type: ElastiCache (Redis)

Opportunity Description:
This Finder identifies Redis ElastiCache clusters that can benefit from enabling data tiering, a cost-saving feature that moves less frequently accessed data from expensive in-memory storage (RAM) to lower-cost SSD storage. AWS ElastiCache data tiering allows customers to significantly reduce costs for large datasets that don’t require all data to reside in memory at all times.

By enabling data tiering, you can reduce the size (and cost) of memory-based nodes and rely on SSDs for cold data access — without compromising application performance.

Criteria for identifying the opportunity:

• Redis ElastiCache cluster must be running Redis version 6.2 or later.
• Instance type must support data tiering (e.g., r6gd node types).
• Cluster workload characteristics show that a significant portion of data remains unused in memory (i.e., low hit ratios or large memory footprint with low activity).
• Sufficient metrics must be available to analyze memory usage and assess data temperature (hot vs. cold).

Potential Savings (if known):
Savings depend on the size of the dataset and node types. Data tiering enables the use of fewer and/or smaller memory nodes while storing cold data on cheaper SSDs. Customers have seen up to 60% reduction in memory costs with no noticeable performance degradation.

What happens when the Fixer is executed?
This Finder does not currently have an automatic Fixer. Enabling data tiering requires a manual upgrade to supported r6gd node types and a configuration change at the cluster level. This involves:

1. Modifying the cluster to use a compatible instance family.
2. Enabling data tiering in the Redis configuration.
3. Restarting or recreating the cluster.

CloudFix will provide detailed migration guidance, or customers can leverage AWS documentation to complete the change.

Is it possible to roll back once CloudFix implements the fixer?
Yes. You can revert to non-tiered nodes by modifying the instance type and disabling the data tiering configuration. However, this involves downtime and reconfiguration.

Can CloudFix implement the fix automatically once I accept the recommendation?
No. This fix must be applied manually or with assistance from CloudFix Professional Services.

Does this fix require downtime?
Yes. Transitioning to new instance types and enabling tiering may require restarting or recreating clusters, resulting in downtime. Plan the change during maintenance windows.

Additional Resources:

• ElastiCache Data Tiering Overview
• Supported Redis Node Types with Data Tiering
• Modifying ElastiCache Clusters