Database cluster has no Multi-AZ failover instance
- Severity
- Low
- Service
- RDS
- Check ID
- RDS_CLUSTER_NOT_MULTI_AZ
What this check finds
A provisioned Aurora/RDS cluster with a single instance has no reader to promote on a primary or Availability Zone failure, causing downtime until a new instance is provisioned. Add at least one replica in a different Availability Zone for automatic failover.
Passing looks like: Database cluster has a Multi-AZ failover instance.
How to fix it
Add a reader instance in another Availability Zone.
AWS CLI
aws rds create-db-instance --db-instance-identifier CLUSTER-reader --db-cluster-identifier CLUSTER_ID --engine ENGINE --db-instance-class db.r6g.large
Names in capitals are placeholders for your own resource. Review a command before you run it.
AWS console
RDS → Databases → select the cluster → Actions → Add reader.
Compliance controls it is evidence for
A failing result counts against these controls in KloudLytics; a passing one is evidence towards them. How compliance mapping works
| Framework | Controls |
|---|---|
| CIS AWS Foundations Benchmark v5.0.0 |
|
| NIST SP 800-53 Rev5 (Moderate) |
|
| NIST Cybersecurity Framework 2.0 |
|
| ISO/IEC 27001:2022 Annex A |
|
Checked on every scan
KloudLytics runs this check each time it scans a connected AWS account, through a read-only role, and lists every affected resource with its region. On Pro and Business a fix is written for the specific resource rather than the general case above. The exact access it needs
More RDS checks
- HighAurora/RDS cluster storage is not encrypted at rest
- HighRDS automated backups are disabled
- HighRDS instance does not have automatic minor version upgrades enabled
- HighRDS instance has zero database connections for 7 days
- HighRDS instance storage is not encrypted at rest
- HighRDS security group allows broad CIDR ingress (broader than /16)
- HighRDS snapshot is public
- MediumAurora/RDS cluster has automated backups disabled