Overview

ElastiCache Rules

CloudBurn cost optimization rules for AWS ElastiCache.

ElastiCache Rules

These rules flag ElastiCache clusters that are running on-demand when reserved node pricing would save you money.

Rule IDScan TypeName
CLDBRN-AWS-ELASTICACHE-1DiscoveryElastiCache Cluster Missing Reserved Coverage

CLDBRN-AWS-ELASTICACHE-1

ElastiCache Cluster Missing Reserved Coverage

Scan type: Discovery

What it checks

Flags ElastiCache clusters that have been running for at least 180 days without matching active reserved node coverage. The rule normalizes node sizes into capacity units and checks whether your reserved inventory covers each cluster's actual footprint.

Valkey clusters can consume reserved coverage from Valkey, Redis, or wildcard engine buckets. Node types with unknown sizes fall back to exact-type matching.

Why it matters

ElastiCache Reserved Nodes offer up to 55% savings over on-demand pricing for 1-year terms and even more for 3-year commitments. A cluster that has been running for 6+ months without reserved coverage is almost certainly a candidate for a reservation. The longer a cluster runs on-demand, the more money you leave on the table.

What triggers a finding

All of the following must be true:

  • Cluster status is available
  • Cluster has been running for more than 180 days
  • The cluster's normalized capacity exceeds the remaining reserved node coverage for its region:nodeType:engine combination

How to remediate

  1. Review the flagged cluster's node type, engine, and node count
  2. Check your current reserved node inventory for gaps in coverage
  3. Purchase a reserved node that matches the cluster's configuration:
aws elasticache purchase-reserved-cache-nodes-offering \
  --reserved-cache-nodes-offering-id <offering-id> \
  --cache-node-count 1

Consider using the AWS Cost Explorer Reserved Instance recommendations to identify the most cost-effective reservation terms for your usage patterns.

See Also

← EKSELB →