Queue Job Visualizer

Enqueue simulated jobs over HTTP, process them asynchronously with a Queues consumer, and track status transitions in KV (queued → processing → done / failed). The consumer simulates ~35% failure rate and retries via message.retry().

Features

• POST /jobs - Enqueue a resize or fetch job
• GET /jobs/:id - Poll job status from KV
• Simulated failures - Consumer retries up to 3 attempts before marking failed
• KV state machine - Full transition history on each job record

API Reference

POST /jobs

Enqueue a new job.

Example Request

curl -X POST "https://your-worker.workers.dev/jobs" \
  -H "Content-Type: application/json" \
  -d '{"type":"fetch","target":"https://example.com/image.png"}'

Success Response (201)

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "type": "fetch",
  "target": "https://example.com/image.png",
  "status": "queued",
  "attempts": 0,
  "enqueuedAt": "2025-06-20T12:00:00.000Z",
  "updatedAt": "2025-06-20T12:00:00.000Z"
}

Error Codes

• 400 - Invalid JSON (INVALID_BODY), type (INVALID_TYPE), or target (INVALID_TARGET)

GET /jobs/:id

Returns the current job record from KV.

Example Request

curl "https://your-worker.workers.dev/jobs/550e8400-e29b-41d4-a716-446655440000"

Success Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "type": "fetch",
  "target": "https://example.com/image.png",
  "status": "done",
  "attempts": 1,
  "result": "Fetched https://example.com/image.png (simulated)",
  "enqueuedAt": "2025-06-20T12:00:00.000Z",
  "updatedAt": "2025-06-20T12:01:00.000Z"
}

Error Codes

• 404 - Job not found (NOT_FOUND)

Use Cases

• Learn Queues producer (send) and consumer (queue() handler) setup
• Visualize async job lifecycles with KV-backed status
• Demonstrate retry semantics with message.retry() and message.ack()

Limitations

• Jobs are simulated; no actual image resize or fetch occurs
• Failure rate is deterministic per job id + attempt (demo only)
• Requires KV namespace and Queue configured in wrangler.json

Deployment

curl -X POST "https://your-worker.workers.dev/jobs" \
  -H "Content-Type: application/json" \
  -d '{"type":"resize","target":"photo.png"}'

Local Development

cd apps/experiments/queue-job-visualizer
npm install
npm run dev

Configuration

Cloudflare Features Used

• Workers - Edge compute runtime
• Queues - Async job processing
• Workers KV - Job status storage