Without a pinned engine version, CloudFormation will pick one at creation time and may change it during subsequent stack updates. Pin to a specific minor version to ensure predictable upgrades and avoid unexpected breaking changes. NOTE: If you are using an Aurora engine (aurora, aurora-mysql, aurora-postgresql), use the Aurora DB Cluster resource instead of RDS DBInstance — the cluster manages the engine version for all instances within it.
Paste into this field
RDS → engineVersionOutput looks like
15.4 (PostgreSQL) or 8.0.35 (MySQL)Navigate to RDS → "Create database" → select your engine. The "Version" dropdown shows all available versions. Note the exact version string (e.g. 15.4 or 8.0.35).
PostgreSQL: 15.x or 16.x (check AWS deprecation schedule for end-of-life dates)
MySQL: 8.0.35 or later
MariaDB: 10.11.x (LTS release)
Select your RDS node → "Engine Version" field → enter the exact version string.
Once you have the value, go back to CloudStack Canvas and paste it into the highlighted field.
CloudStack Canvas · Validation Guide