Failing fast when Redis is down

By design, BullMQ reconnects to Redis automatically. If jobs are added to a queue while the queue instance is disconnected from Redis, the add command will not fail; instead, the call will keep waiting for a reconnection to occur until it can complete.

This behavior is not always desirable; for example, if you have implemented a REST API that results in a call to add, you do not want to keep the HTTP call busy while add is waiting for the queue to reconnect to Redis. In this case, you can pass the option enableOfflineQueue: false, so that ioredis do not queue the commands and instead throws an exception:

const myQueue = new Queue("transcoding", {
  connection: {
    enableOfflineQueue: false,
  },
});

app.post("/jobs", async (req, res) => {
  try {
    const job = await myQueue.add("myjob", { req.body });
    res.status(201).json(job.id);
  }catch(err){
    res.status(503).send(err);
  }
})

Using this approach, the caller can catch the exception and act upon it depending on its requirements (for example, retrying the call or giving up).

Currently, there is a limitation in that the Redis instance must at least be online while the queue is being instantiated.