Migrate Google Cloud SQL for PostgreSQL: Transactional workflows

Move PostgreSQL data from Google Cloud SQL for PostgreSQL to Ample, one component at a time. Destination verified on Ample: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected).

Source procedure

Take a logical backup with pg_dump -Fc through the Cloud SQL Auth Proxy or an authorized network. Not migrated automatically: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR have no equivalent on the managed database.

Cutover

Freeze writes with the user's go-ahead, take the final dump, restore, validate, redeploy with the managed DATABASE_URL, keep Cloud SQL until confirmed.

Rollback

Keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Workflow Steps

1. Inventory the source
   List what Google Cloud SQL for PostgreSQL provides beyond the component you are moving. Out of scope here: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR have no equivalent on the managed database.

2. Source step 1
   Take a logical backup with pg_dump -Fc through the Cloud SQL Auth Proxy or an authorized network.

3. Source step 2
   Check the engine major version, extensions and flags the app depends on.

4. Source step 3
   Restore into a scratch managed database first and compare row counts.

5. Provision and restore
   Deploy the app once so a managed PostgreSQL 16 database exists (or create one with ample database create --engine postgres), then restore the dump with pg_restore using its connection string; keep migrations idempotent.

   Command: ample database create --name --engine postgres

6. Validate before cutover
   Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/transactional-workflows).

7. Cut over
   Freeze writes with the user's go-ahead, take the final dump, restore, validate, redeploy with the managed DATABASE_URL, keep Cloud SQL until confirmed.

8. Rollback
   Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

Limitations

• Documentation only: nothing is executed automatically and no execution binding is offered.
• The source-side procedure is documented from Google Cloud SQL for PostgreSQL's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture.
• No full source-product parity is claimed: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR have no equivalent on the managed database.
• Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures on the managed side are not verified beyond the pattern checks.

Success Checks

• Destination app responds on its public URL
  Type: http_get
  Path: /
  Expect: ample canary express patterns

• Transactional-workflows check from the destination example
  Type: http_get
  Path: /p/transactional-workflows
  Expect: see the pattern fixture checks

• Data or object counts and checksums match the source
  Type: manual
  Expect: operator comparison before cutover.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty

Components

• App server: size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0
• Managed PostgreSQL database: size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0

Note: Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample.

Example

• Title: Express pattern fixture (destination)
  Description: Verified destination basis: transactional workflows.
  Source Reference: tests/deploy-canaries/express-patterns

Evidence Summary

• Kind: canary_run
  Summary: Destination side verified: the Express pattern fixture deployed on Ample (npm install, npm run build --if-present, npm run start on the node-22 template) and its checks passed (an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected)). The source-side export from Google Cloud SQL for PostgreSQL is documented from the vendor's standard tooling and was not executed by this catalog's evidence.
  Observed At: 2026-09-21T02:34:39Z
  Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)
  Expires At: 2027-03-20T02:34:39Z
  Scope: { "checks": ["/p/transactional-workflows"], "destinationOnly": true, "template": "node-22" }

Last Verified At

2026-09-21T02:34:39Z

Unknowns

• Region availability is unknown until a verified region fact is recorded.
• Compliance attestations are unknown; none are claimed.