# Amazon ElastiCache Cluster

> ElastiCache bills per node-hour by node type for as long as a cluster exists. AWS offers no stop operation, so an idle cache bills 24/7 until deleted or resized. ZopNight tracks 90 days of node metrics and recommends idle-cluster removal, rightsizing, and Graviton node types instead of scheduling.

Source: https://zop.dev/integrations/aws/elasticache
Updated: 2026-08-19

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Amazon ElastiCache runs managed Redis and Memcached clusters billed per node-hour. Cache nodes cannot be natively stopped, only deleted, so oversized or idle caches accumulate cost until someone rightsizes or removes them.

## A meter with no pause

Every node in a cluster bills its per-node-hour rate from creation to deletion. There is no stop API, and the choice is running or gone, which makes ElastiCache unusual among stateful services: an idle cache bills all 168 hours of every week until a human intervenes. Backup storage beyond the free allowance adds a per-GB-month meter. Reserved nodes lower the hourly rate for steady production caches, which sharpens the question an idle one raises: a cache that cannot be stopped should either be reserved or challenged.

## Why ZopNight does not schedule it

A scheduling executor exists for ElastiCache but is a deliberate no-op placeholder, precisely because there is no native stop operation to call. Deleting and recreating a cache nightly would drop the entire dataset and force a cold-start repopulation every morning, so the safe cost levers are rightsizing and removal, never scheduling.

## The three usual findings

Idle clusters: nodes serving near-zero commands for weeks, typically left behind by a decommissioned application. Multi-AZ replica nodes protecting caches whose data is disposable by definition. And older non-Graviton node families paying more per node-hour than the equivalent Graviton generation for the same memory.

## Tracking an unstoppable meter

Clusters are discovered every 6 hours via Resource Explorer 2, with hourly CloudWatch metrics from the ElastiCache namespace kept over a 90-day lookback and per-cluster cost from Cost Explorer or CUR 2.0. Recommendations cover idle clusters, node rightsizing, and Graviton node types.

## Cache inventory in the console

ElastiCache console, then Redis OSS caches or Memcached caches in the left navigation. A cluster's node type and node count, the two multiplicands of its bill, sit on the cluster detail page.