/async-jobs

name: async-jobs
license: MIT
compatibility: "Claude Code 2.1.251+."
description: Async job processing patterns for background tasks, Celery workflows, task scheduling, retry strategies, and distributed task execution. Use when implementing background job processing, task queues, or scheduled task systems.
tags: [async, jobs, celery, background-tasks, scheduling, queues]
context: fork
agent: python-performance-engineer
version: 2.0.0
author: OrchestKit
user-invocable: false
disable-model-invocation: true
complexity: medium
persuasion-type: reference
metadata:
  category: workflow-automation
allowed-tools:
  - Read
  - Glob
  - Grep
  - WebFetch
  - WebSearch

Async Jobs

Background task processing with Celery, ARQ, Redis and Temporal. This skill is a wrapper, not a manual: Celery and ARQ document their own product well, so what lives here is our delta, the thresholds, working config, ordering constraints and tool-choice rules we picked. Product mechanics are linked, not restated.

Start with `Read("references/ork-delta.md")`.

Quick Reference

| Topic | Where our part lives | |-------|----------------------| | [Configuration](#configuration) | `references/celery-config.md`, `rules/jobs-task-queue.md` | | [Task Routing](#task-routing) | `references/ork-delta.md` (queue taxonomy, prefetch tiers, Redis priority) | | [Canvas Workflows](#canvas-workflows) | `rules/celery-canvas.md` | | [Retry Strategies](#retry-strategies) | `references/ork-delta.md` (backoff cap, idempotency layers, lock TTLs) | | [Scheduling](#scheduling) | `rules/jobs-scheduling.md`, `references/ork-delta.md` (beat process model) | | [Monitoring](#monitoring) | `references/ork-delta.md` (alert thresholds, histogram buckets) | | [Result Backends](#result-backends) | `rules/jobs-monitoring.md`, `references/ork-delta.md` (return contract) | | [ARQ Patterns](#arq-patterns) | `rules/jobs-task-queue.md`, `references/ork-delta.md` (budgets, pool ownership) | | [Temporal Workflows](#temporal-workflows) | `rules/temporal-workflows.md` | | [Temporal Activities](#temporal-activities) | `rules/temporal-activities.md` |

10 topic areas, 6 rule files in `rules/`, house delta in `references/ork-delta.md`.

Quick Start

@app.task(bind=True, max_retries=3, default_retry_delay=60)
def process_payment(self, order_id: str):
    try:
        return gateway.charge(order_id)
    except TransientError as exc:
        raise self.retry(exc=exc, countdown=2 ** self.request.retries * 60)

Load more examples: `Read("references/quick-start-examples.md")` for Celery retry task and ARQ/FastAPI integration patterns.

Upstream coverage (do not restate)

Fetch these when you need product mechanics. The right-hand column is the part we keep, because it is a house threshold, a working config or an ordering constraint that upstream cannot know.

| Topic | First-party source | House subset stays in | |-------|--------------------|-----------------------| | Celery settings, serializers, time limits, worker flags | https://docs.celeryq.dev/en/stable/userguide/configuration.html and .../optimizing.html | `references/celery-config.md`, `rules/jobs-task-queue.md` | | Queue declarations, router classes, Redis priority mechanics | https://docs.celeryq.dev/en/stable/userguide/routing.html | `references/ork-delta.md` | | chain / group / chord / signature semantics | https://docs.celeryq.dev/en/stable/userguide/canvas.html | `rules/celery-canvas.md` keeps the house canvas subset. Its `si()`-in-chords guidance is UNVERIFIED and contested: confirm the argument-passing behaviour against the upstream canvas page before relying on it | | `autoretry_for`, `retry_backoff`, `Reject`, task base classes | https://docs.celeryq.dev/en/stable/userguide/tasks.html | `references/ork-delta.md`, `rules/jobs-task-queue.md` | | Beat schedules, crontab syntax, DatabaseScheduler | https://docs.celeryq.dev/en/stable/userguide/periodic-tasks.html and https://django-celery-beat.readthedocs.io/en/latest/ | `rules/jobs-scheduling.md` keeps our `beat_schedule` shapes; `references/ork-delta.md` keeps the process model | | Flower flags, `inspect`, signal names | https://docs.celeryq.dev/en/stable/userguide/monitoring.html, https://docs.celeryq.dev/en/stable/userguide/signals.html, https://flower.readthedocs.io/en/latest/config.html | `references/ork-delta.md` | | Result backend, `AsyncResult`, custom states | https://docs.celeryq.dev/en/stable/userguide/configuration.html | `rules/jobs-monitoring.md` keeps our status endpoints and `update_state()` usage | | Per-task `rate_limit`, `control.rate_limit`, Redis Lua | https://docs.celeryq.dev/en/stable/userguide/workers.html, https://redis.io/docs/latest/develop/programmability/eval-intro/ | `references/ork-delta.md` | | ARQ `WorkerSettings`, `enqueue_job`, `_defer_by` / `_defer_until`, `Job` status | https://arq-docs.helpmanual.io/ | `rules/jobs-task-queue.md` keeps the worker skeleton; `references/ork-delta.md` keeps the budgets | | FastAPI lifespan and dependency wiring | https://fastapi.tiangolo.com/advanced/events/ | `references/ork-delta.md` | | Distributed locks with `SET NX EX` | https://redis.io/docs/latest/commands/set/ | `references/ork-delta.md` |

Configuration

Load: `Read("references/celery-config.md")`.

| Decision | Recommendation | |----------|----------------| | Serializer | JSON (never pickle) | | Ack mode | Late ack (`task_acks_late=True`) | | Prefetch | 1 for fair, 4-8 for throughput | | Time limit | soft < hard (540 / 600) | | Timezone | UTC always |

Task Routing

| Decision | Recommendation | |----------|----------------| | Queue count | 5: critical / high / default / low / bulk | | Priority levels | 0-9, with all four Redis priority switches set together | | Worker assignment | Dedicated worker per queue | | Prefetch | 1 critical, 2 high, 4 default, 8 low/bulk | | Routing | Router class once past 5 routing rules |

Canvas Workflows

Load: `Read("rules/celery-canvas.md")`.

| Decision | R