Description
A snapshotRetentionLimit of 0 disables automatic snapshot backups for ElastiCache Redis. If the cache holds recoverable state such as sessions or queues, missing backups can limit available recovery points.
Potential impact
- Recovering required data after a failure or incorrect change can become difficult.
- Rebuilding the cache from source data can extend recovery time and service disruption.
Remediation
Where automatic backups are needed, set snapshotRetentionLimit to a supported value of at least one day. Select retention according to recovery objectives, and verify actual snapshot creation and restore procedures.
Examples
These excerpts compare automatic snapshot retention. Configure the node type and other settings separately. Five days is an example, not a recommendation for every service.
Before
resources:
example:
type: aws:elasticache:Cluster
properties:
engine: redis
snapshotRetentionLimit: 0
After
resources:
example:
type: aws:elasticache:Cluster
properties:
engine: redis
snapshotRetentionLimit: 5
The after example retains automatic snapshots for five days. It does not guarantee recovery of every change since the last backup or automatic service recovery.