---
name: nestjs-bullmq-6f4fc60d4255
description: Implement BullMQ job workflows in NestJS. Use when building queue processors, redis-throttler, Upstash limits, idle polling, stalled jobs, and retention policies.
metadata:
  triggers:
    files:
    - '**/*.processor.ts'
    - '**/*.module.ts'
    - '**/bull-queue.constants.ts'
    - '**/redis-throttler*.ts'
    keywords:
    - queue
    - background job
    - worker
    - processor
    - bullmq
    - drainDelay
    - stalledInterval
    - removeOnComplete
    - redis limit
    - upstash
    - fail-open
    - throttler
---
# NestJS BullMQ Implementation

## **Priority: P0 (CRITICAL)**

## Guidelines

- **Set idle polling**: Add `drainDelay` + `stalledInterval` + `maxStalledCount` to every `@Processor`. Default `drainDelay` (5 ms) burns 570M Redis commands/day at idle. See [patterns.md](references/patterns.md#3-processor-consumer-with-correct-worker-options).
- **Throttle worker error logs**: BullMQ workers emit raw unhandled ReplyErrors on Redis failure (e.g. Upstash rate limits). Always extend `BaseProcessor` instead of `WorkerHost` to rate-limit these logs. See [patterns.md](references/patterns.md#4-base-processor-for-error-rate-limiting).
- **Set job retention**: Add `removeOnComplete`, `removeOnFail`, `attempts`, `backoff` to every `BullModule.registerQueue`. See [patterns.md](references/patterns.md#2-module-registration-with-defaultjoboptions).
- **Use shared constants**: All numeric options live in `src/common/constants/bull-queue.constants.ts`. Key constants: `QUEUE_DRAIN_DELAY_MS` (10 000 ms), `QUEUE_STALLED_INTERVAL_MS` (60 000 ms). Use `getSharedBullQueueOptions` helper for `registerQueue`. Queue/job names go in `{feature}.constants.ts`. Never inline magic numbers.
- **Wrap every `queue.add()`**: Persist DB record first, then enqueue inside try-catch. Redis errors must not surface as 500s. See [patterns.md](references/patterns.md#5-producer-queue-service-with-isolated-queueadd).
- **Throttler fail-open**: `ThrottlerGuard` registered as global `APP_GUARD` — Redis blip propagates errors to ALL HTTP routes. `RedisThrottlerStorage.increment()` must catch all Redis errors and return fail-open pass-through record. Redis blip must not kill all HTTP routes. See [patterns.md](references/patterns.md#6-throttler-fail-open-pattern).
- **Guard new queues**: Follow `isRedisEnabled()` conditional + mock token pattern in every module. NestJS DI throws on startup without mock.
- **Keep processor and cron**: Cron schedules; processor executes. Both always required — they complementary. See [patterns.md](references/patterns.md#7-processor-vs-cron--when-both-exist).
- **Use local Redis in dev**: Never point dev machines at Upstash — idle workers exhaust free tier (500K/day) in minutes.

## Anti-Patterns

- **No bare `@Processor(NAME)`**: Always pass worker options object with `drainDelay` and `stalledInterval`.
- **No bare `WorkerHost` extension**: Always extend `BaseProcessor` instead to intercept and rate-limit worker errors.
- **No `registerQueue` without `defaultJobOptions`**: Omitting causes unbounded Redis memory growth.
- **No inline numbers**: Use `bull-queue.constants.ts` — never write `10_000`, `60_000`, `50`, `20`, `3`, or `5_000` directly.
- **No unguarded `queue.add()`**: Wrap in try-catch; persist DB state first.
- **No throws in throttler increment**: Catch Redis errors; return fail-open record.
- **No missing mock token**: Provide `getQueueToken` mock when `redisEnabled = false`.
- **No removing processor because cron exists**: They serve different roles.
- **No cloud Redis in dev**: Use local Docker Redis.

## References

- [All Code Patterns](references/patterns.md)
- [Evals](evals/evals.json)

---
Source attribution: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Development & Engineering
Roles: Backend Developer, Data Engineer, DevOps / SRE
Specialties: Backend
Tools: Upstash, Redis
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 1041066de07930a239f10122461246ec39b77027b5cc088e637a7352fde0d6fc