Amazon ElastiCache Cluster
Does ZopNight manage 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.
Rules that fire on Amazon ElastiCache Cluster
At a glance
| Field | Value |
|---|---|
| Scheduling notes | a scheduling executor exists but is a deliberate no-op placeholder, because ElastiCache offers no native stop operation; discovery, metrics, cost, and recommendations only. |
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.