page:recipes:rest api:spring boot:persistent state

Host rest api with Spring Boot: Postgres-backed state

Deploy a rest api built with Spring Boot on Ample using the durable job state pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Spring Boot: 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). Not separately tested: your job types, payload schema and retry policy; treat the rest api-specific behavior as your application code.

Representative Queries

• Host rest api with Spring Boot: Postgres-backed state
• Where can I host REST API built with Spring Boot?
• I need a durable state schema and retry/recovery semantics implemented by application code.

Resource Requirements

• Primitive: Compute
• Primitive: Postgres

Infrastructure Requirements

1. Compute
   • Status: verified
   • Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. Postgres
   • Status: verified
   • Summary: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

Prerequisites

• A Spring Boot project that builds and starts with the documented commands (./mvnw -q -DskipTests package or the Gradle wrapper) producing one application jar, then java -jar on the jvm-21 template (Temurin JDK 21) with server.port read from PORT.
• A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env).
• An Ample account token with servers:write, databases:read.

Tested Configuration

• Template: jvm-21
• Runtime: java
• Size: s-1vcpu-2gb
• Build command: ./mvnw -q -DskipTests package
• Start command: java -jar $(ls target/*.jar | grep -v -- '-plain' | head -n 1)

Workflow Steps

1. Build and start
   • Command: ./mvnw -q -DskipTests package (or the Gradle wrapper) producing one application jar, then java -jar on the jvm-21 template with server.port read from PORT. The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL
   • The fixture's module implements durable job state: 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). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. Deploy
   • Command: ample deploy . --name <name> --public
4. Verify
   • Verify the app responds on its public URL. Fetch the live URL and the pattern self-test route(s) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.

Examples

• Title: Spring Boot pattern fixture
  Description: Multi-pattern Spring Boot app whose durable job state module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
  Source Reference: tests/deploy-canaries/spring-boot-patterns

Success Checks

1. Description: app responds on its public URL
   • Kind: http_get
   • Path: /
   • Expect: ample canary spring boot patterns
2. Description: durable-job-state self-test
   • Kind: http_get
   • Path: /p/durable-job-state
   • Expect: job=done attempts=1 idempotent=true

Limitations

• Verified on the jvm-21 template at s-1vcpu-2gb with the example fixture; other sizes, templates and Spring Boot major versions are not verified.
• The rest api itself (your job types, payload schema and retry policy) is application code and was not separately tested; the pattern checks are what was verified.
• Region, compliance attestations and request-duration limits are unknown and not claimed.
• Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Basis: size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  1. Name: app server
     • Size: s-1vcpu-1gb
     • Quantity: 1.0
     • Monthly Amount: 5.0
  2. Name: managed PostgreSQL database
     • Size: s-1vcpu-1gb
     • Quantity: 1.0
     • Monthly Amount: 5.0
• Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

Evidence Summary

• Kind: canary_run
  Summary: Spring Boot pattern fixture deployed on Ample (checks passed for durable-job-state and configuration-secrets).
  Observed At: 2026-09-21T02:34:39Z
  Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)
  Expires At: 2027-03-20T02:34:39Z
• Kind: canary_run
  Summary: The same Spring Boot app deployed with a --release-command migration; the marker it created was readable after activation.
  Observed At: 2026-09-20T22:49:19Z
  Implementation Revision: af6f45adea26-dirty (CLI af6f45a)
  Expires At: 2027-03-19T22:49:19Z

Next Actions

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