Queue System

The service includes a built-in job queue with priority support, status tracking, and automatic persistence.

Features

• Priority Support: Jobs with higher priority (1-10) are processed first
• Status Tracking: Track job progress from queued to completed
• Cancellation: Cancel pending or processing jobs
• Persistence: Queue state survives service restarts

Queue Persistence

Queue state is saved to data/queue.json and restored on service restart:

• Processing jobs are reset to "queued" on restart
• Completed/failed jobs are preserved
• Automatic retry on failure

Queue Statistics

Get queue statistics via API:

GET /api/pdf/queue

Response:

{
  "total": 10,
  "queued": 5,
  "processing": 2,
  "completed": 2,
  "failed": 1,
  "cancelled": 0
}

Priority

Use the priority option to control job processing order:

{
  "requestedKey": "urgent-report",
  "url": "https://example.com",
  "options": {
    "queue": {
      "priority": 10
    }
  }
}

Priority levels: 1 (lowest) to 10 (highest). Default is 5.