BullMQ worker with retries + dead-letter

8833 views

                  import { Queue, Worker } from 'bullmq';
import IORedis from 'ioredis';

const connection = new IORedis(process.env.REDIS_URL!);

export const emailQueue = new Queue('email', { connection });

export const emailWorker = new Worker(
  'email',
  async (job) => {
    // sendEmail(job.data)
    return { sent: true };
  },
  {
    connection,
    concurrency: 5
  }
);

emailWorker.on('failed', async (job, err) => {
  if (!job) return;
  if ((job.attemptsMade ?? 0) >= (job.opts.attempts ?? 1)) {
    // dead-letter pattern: re-enqueue into a separate queue for investigation
    await new Queue('email-dlq', { connection }).add('dead', { original: job.data, error: err.message });
  }
});

Background jobs will fail in production, so I like having a predictable story for retries and poison messages. BullMQ is a solid middle ground: Redis-backed, straightforward, and good enough for most apps. I set explicit attempts and backoff, and when a job keeps failing I push it to a DLQ (dead-letter queue) for human inspection instead of retrying forever. For side-effecting work (emails, payments), I include an idempotency key in the job payload and design the handler to be safe on re-run. The core insight is that retries must be safe by design—don’t rely on ‘it probably won’t run twice’, because eventually it will.

Mateo Rodriguez

More from Mateo Rodriguez

BullMQ worker with retries + dead-letter

0 Comments

More from Mateo Rodriguez