page:recipes:graphql api:spring boot:worker state

Host graphql api with Spring Boot: worker execution and job state

Deploy a graphql api built with Spring Boot as a public web service plus a dedicated worker process on Ample. ample plan --write discovers both services and their shared database and writes ample.toml; ample up reconciles the topology: a managed PostgreSQL 16 database, a public web microVM and a private worker microVM (kind worker, no public URL), both reading DATABASE_URL. Verified on Spring Boot: a separately deployed worker service (kind worker, no public URL) sharing a declared managed PostgreSQL database with the web service, consuming a jobs table with row locks and marking jobs done once (worker=done attempts=1). Not separately tested: your job payloads, retry policy and scheduling; treat the graphql api-specific behavior as your application code.

Representative Queries

• Host graphql api with Spring Boot: worker execution and job state
• Where can I host GraphQL API built with Spring Boot?
• I need a separately runnable worker, durable job records and idempotent retries; not a managed queue.

Resource Requirements

• primitive:compute
• primitive:postgres

Infrastructure Requirements

1. Compute: 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: 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 repository with the web app and the worker as separate service directories (the fixture uses apps/web and apps/worker), each building and starting with the documented commands.
• Both services read DATABASE_URL at runtime and share one jobs table; the worker claims rows with SELECT ... FOR UPDATE SKIP LOCKED and marks them done once.
• An Ample account token with servers:write and databases:write (ample up creates the database).

Workflow Steps

1. Plan the topology: Run the planner once. It discovers the web and worker services, infers kind = "worker" for the process without a port, declares the database each service needs, and writes ample.toml. Exit 2 means it left questions in the manifest; answer them with --answer or by editing the file.

   ample plan --write .
   

2. Share one database: Keep a single [databases.main] with engine = "postgres", drop any per-service database the planner added, and set DATABASE_URL = { database = "main" } under both [services.web.env] and [services.worker.env].

   ample plan --offline .
   

3. Apply: Reconcile the whole manifest in dependency order: the database first, then both services. It is idempotent and never destructive; exit 0 means everything applied, 2 needs input, 1 a failed resource.

   ample up .
   

4. Verify: Fetch the web service URL and its worker status route (/p/worker-queue/status in the example) and confirm the worker processed the enqueued job; on failure read the worker service's runtime logs.

   ample logs  --kind runtime
   

Limitations

• Verified on the jvm-21 template at s-1vcpu-2gb for both services with the example fixture; other sizes, templates, and Spring Boot major versions are not verified.
• The graphql api itself (your job payloads, retry policy and scheduling) is application code and was not separately tested.
• The worker is a single long-running process supervised in its own microVM; there is no scheduler, cron or horizontal worker scaling in this recipe.

Cost Estimate

• Currency: USD
• Monthly Amount: 15.0
• Basis: size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  • web server: s-1vcpu-1gb (quantity 1.0, monthly amount 5.0)
  • worker 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: Always-on monthly price of the tested sizes for the web service, the worker service and the database; apps auto-pause when idle.