code

python queuectl.py init-db --db ./queue.db

  # Enqueue a job (command string)
  python queuectl.py enqueue --db ./queue.db --command "echo 'Hello World'" --max-retries 3

  # Enqueue job with JSON payload
  python queuectl.py enqueue --db ./queue.db --json '{"id":"job-1","command":"ls -la","max_retries":2}'

  # Start 4 workers
  python queuectl.py start-workers --db ./queue.db --workers 4

  # List pending/running jobs
  python queuectl.py list --db ./queue.db --state pending

  # Show DLQ
  python queuectl.py dlq-list --db ./queue.db

  # Requeue a DLQ job
  python queuectl.py requeue-dlq --db ./queue.db --job-id <JOB_ID>

  # Retry a specific job (force)
  python queuectl.py retry-job --db ./queue.db --job-id <JOB_ID>

Notes:
 - SQLite is used for persistence (file DB).
 - Workers claim jobs atomically using an UPDATE ... WHERE ... AND state='pending' AND next_run_at<=now
 - Exponential backoff: base_delay * (2 ** attempts) with optional jitter (randomized small fraction)
 - When attempts > max_retries job is moved to DLQ.