page:recipes:mcp server:axum:worker state
Host mcp server with Axum: worker execution and job state
Deploy a mcp server built with Axum 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 Axum: 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 mcp server-specific behavior as your application code.
Representative Queries
- Host mcp server with Axum: worker execution and job state
- Where can I host MCP server built with Axum?
- I need a separately runnable worker, durable job records and idempotent retries; not a managed queue.
Resource Requirements
- Compute
- Postgres
Infrastructure Requirements
- Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- 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.
Workflow Steps
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.
Command:ample plan --write .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].
Command:ample plan --offline .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 (independent siblings still proceed and re-running resumes).
Command:ample up .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.
Command:ample logs --kind runtime
Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-2gb for both services with the example fixture; other sizes, templates and Axum major versions are not verified.
- The mcp server itself (your job payloads, retry policy and scheduling) is application code and was not separately tested; the worker-queue check is what was verified.
- 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, and the check ran immediately after deploy so idle behavior of the worker VM is not verified.
- The worker service is private: it has no public URL and is reached only through the shared database; both services are placed with their database.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.