Host rest api with Spring Boot: streamed responses

Summary

Deploy a rest api built with Spring Boot on Ample using the streaming response service 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 Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Not separately tested: your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured; treat the rest api-specific behavior as your application code.

Representative Queries

• Host rest api with Spring Boot: streamed responses
• Where can I host REST API built with Spring Boot?
• I need a tested end-to-end streaming transport, timeout behavior, and client disconnect handling.

Resource Requirements

• primitive:compute
• primitive: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.

Framework

Spring Boot

Workload

REST API

Release Status

published

Support Status

verified

Execution Status

ready

Prerequisites

1. 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)
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
3. An Ample account token with servers:write, databases:read

Tested Configuration

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

Workflow Steps

1. Build and start: ./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. The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL: The fixture's module implements streaming response service: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. Deploy: Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op. Command: ample deploy . --name --public
4. Verify: Fetch the live URL and the pattern self-test route(s) (/p/streaming-response-service) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime. Command: ample logs --kind build

Examples

• Spring Boot pattern fixture: Multi-pattern Spring Boot app whose streaming response service module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Success Checks

1. app responds on its public URL: kind: http_get, path: /, expect: ample canary spring boot patterns
2. streaming-response-service self-test: kind: http_get, path: /p/streaming-response-service, expect: an SSE stream: data: id=, then chunk events one interval apart (read incrementally: first chunk within seconds, chunks spread over the interval), then data: done; /status?id= reports sent=N disconnected=true|false done=true|false

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 event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured) 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 (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: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

Evidence Summary

1. Kind: canary_run, Summary: Spring Boot pattern fixture deployed on Ample; checks passed for streaming-response-service and configuration-secrets. Observed At: 2026-09-21T02:34:39Z
2. 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

Unknowns

• region availability is unknown until a verified region fact is recorded
• compliance attestations are unknown; none are claimed

Formats

• HTML Format
• Markdown Format
• JSON Format

Next Actions

1. Browse the catalog index - GET /v1/catalog
2. Search published recipes by intent, stack and constraints - POST /v1/catalog/search
3. Prepare a side-effect-free deployment plan for an authorized project - POST /v1/catalog/plan
4. Read the existing agent authentication setup - GET /mcp/setup
5. Browse REST API - GET /v1/catalog/nodes/workload%3Arest-api
6. Browse Spring Boot - GET /v1/catalog/nodes/stack%3Aframework-spring-boot
7. Browse Streaming response service - GET /v1/catalog/nodes/pattern%3Astreaming-response-service
8. Browse Deploy API - GET /v1/catalog/nodes/intent%3Adeploy-api