# Migrate Heroku Postgres: Durable job state

Move PostgreSQL data from Heroku Postgres to Ample, one component at a time. Destination verified on Ample: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true).

## Source Procedure
Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`. Not migrated automatically: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database.

## Cutover
Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database until confirmed.

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

### Prerequisites
- Authorized access to the Heroku Postgres source and its export tooling
- An inventory of every component in scope and out of scope
- A validated backup or copy before any cutover
- An Ample account token with `servers:write`, `databases:read`

### Workflow Steps
1. **Inventory the source**: List what Heroku Postgres provides beyond the component you are moving. Out of scope here: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database.
2. **Source step 1**: Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`.
3. **Source step 2**: Check the Postgres major version and extensions against the managed engine (PostgreSQL 16).
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.
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/durable-job-state`).
7. **Cut over**: Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database 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.

### Success Checks
- Destination app responds on its public URL
- Durable-job-state check from the destination example
- Data or object counts and checksums match the source

### Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Heroku Postgres's standard tooling and was not executed in this catalog's evidence.
- No full source-product parity is claimed: Heroku Postgres followers, forks, rollback (PITR) and dataclips 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.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Basis**: Size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components**:
  - *app server*: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
  - *managed PostgreSQL database*: s-1vcpu-1gb, quantity: 1.0, monthly amount: 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: durable job state.

### Evidence Summary
- **Kind**: canary_run
- **Summary**: Destination side verified: the Express pattern fixture deployed on Ample and its checks passed.
- **Last Verified At**: 2026-09-21T02:34:39Z

### Formats
- **HTML**: [View Documentation](/content/migrate/heroku-postgres/durable-job-state/index.html)
- **Markdown**: [Download Markdown](/content/migrate/heroku-postgres/durable-job-state.md)
- **JSON**: [API Endpoint](https://api.ample.computer/v1/catalog/recipes/page%3Amigrate%3Aheroku-postgres%3Adurable-job-state)

### Next Actions
- **Browse the catalog index**: GET /v1/catalog
- **Search recipes by intent**: POST /v1/catalog/search
- **Prepare deployment plan**: POST /v1/catalog/plan