Connections

In order to start working with a Queue, a connection to a Redis instance is necessary. By default, BullMQ creates connections with ioredis, and the options you pass to BullMQ are passed to the ioredis constructor. If you do not provide any options, it will default to port 6379 and localhost.

BullMQ can also use other Redis clients through its Redis client adapter interface. The package includes adapters for ioredis, node-redis, and Bun's built-in Redis client. You can also provide your own adapter by implementing the IRedisClient interface.

Every class will consume at least one Redis connection, but it is also possible to reuse connections in some situations. For example, the Queue and Worker classes can accept an existing adapted Redis client. Classes that need blocking Redis commands, such as Worker and QueueEvents, will create duplicated connections internally, so the client or adapter must support duplicate().

Some examples:

import { Queue, Worker } from 'bullmq';

// Create a new connection in every instance
const myQueue = new Queue('myqueue', {
  connection: {
    host: 'myredis.taskforce.run',
    port: 32856,
  },
});

const myWorker = new Worker('myqueue', async job => {}, {
  connection: {
    host: 'myredis.taskforce.run',
    port: 32856,
  },
});

Reusing an ioredis connection

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

const connection = new IORedis();

// Reuse the ioredis instance in 2 different producers
const myFirstQueue = new Queue('myFirstQueue', { connection });
const mySecondQueue = new Queue('mySecondQueue', { connection });

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

const connection = new IORedis({ maxRetriesPerRequest: null });

// Reuse the ioredis instance in 2 different consumers
const myFirstWorker = new Worker('myFirstWorker', async job => {}, {
  connection,
});
const mySecondWorker = new Worker('mySecondWorker', async job => {}, {
  connection,
});

Note that in the third example, even though the ioredis instance is being reused, the worker will create a duplicated connection that it needs internally to make blocking connections. Consult the ioredis documentation to learn how to properly create an instance of IORedis.

For backwards compatibility, BullMQ continues to accept a raw IORedis instance via the connection option even though internally it now relies on the IRedisClient adapter interface. To bridge the two, the instance is wrapped in a transparent proxy that exposes IRedisClient: it adds runCommand for Lua script dispatch and structured-options forms of hset, set, zrange, zrevrange, xadd, xread, xtrim, and scan (the native ioredis varargs forms keep working). pipeline() and multi() return augmented transactions, and duplicate() returns another wrapped proxy rather than the raw duplicated client. Every other property — events, options, ioredis-specific methods — is forwarded straight to your underlying instance, which is never mutated.

Using node-redis

BullMQ does not create node-redis clients directly. Create the raw client in your application and wrap it with createNodeRedisClient before passing it to BullMQ.

When using BullMQ's node-redis adapter, install redis v5 or newer. BullMQ declares redis >= 5.0.0 as a peer dependency for this adapter.

import { Queue, Worker, createNodeRedisClient } from 'bullmq';
import { createClient } from 'redis';

const rawClient = createClient({
  url: 'redis://localhost:6379',
});

const connection = createNodeRedisClient(rawClient);

const myQueue = new Queue('myqueue', { connection });
const myWorker = new Worker('myqueue', async job => {}, { connection });

Using Bun's Redis client

Bun has a built-in Redis client. Wrap it with createBunRedisClient before passing it to BullMQ.

import { RedisClient } from 'bun';
import { Queue, Worker, createBunRedisClient } from 'bullmq';

const rawClient = new RedisClient('redis://localhost:6379');
const connection = createBunRedisClient(rawClient);

const myQueue = new Queue('myqueue', { connection });
const myWorker = new Worker('myqueue', async job => {}, { connection });

BullMQ does not instantiate Bun's client for you. Create the raw Bun client in your application and wrap it with createBunRedisClient.

The RedisClient class is provided by Bun runtime. Run this code in Bun (bun run ...), not plain Node.js.

Creating clients globally

If you want BullMQ to create a non-ioredis client whenever it needs a new Redis connection, set RedisConnection.clientFactory during application startup. The factory receives the merged connection options and must return an IRedisClient.

import { Queue, RedisConnection, createNodeRedisClient } from 'bullmq';
import { createClient } from 'redis';

RedisConnection.clientFactory = opts => {
  const rawClient = createClient({
    socket: {
      host: opts.host,
      port: opts.port,
    },
    username: opts.username,
    password: opts.password,
    database: opts.db,
  });

  return createNodeRedisClient(rawClient);
};

const myQueue = new Queue('myqueue', {
  connection: {
    host: 'myredis.taskforce.run',
    port: 32856,
  },
});

You can do the same with Bun's Redis client:

import { RedisClient } from 'bun';
import { Queue, RedisConnection, createBunRedisClient } from 'bullmq';

RedisConnection.clientFactory = opts => {
  const host = opts?.host ?? 'localhost';
  const port = opts?.port ?? 6379;
  const rawClient = new RedisClient(`redis://${host}:${port}`);

  return createBunRedisClient(rawClient);
};

const myQueue = new Queue('myqueue', {
  connection: {
    host: 'myredis.taskforce.run',
    port: 32856,
  },
});

Custom Redis clients

Any Redis client can be used if it is adapted to BullMQ's IRedisClient interface. The adapter is responsible for exposing the Redis commands BullMQ uses, connection lifecycle methods, events, duplicate(), Lua script registration through defineCommand(), and pipelines or transactions through multi() and pipeline().

For most applications, prefer one of the built-in adapters:

• createIORedisClient for ioredis Redis and Cluster instances.

• createNodeRedisClient for node-redis clients.

• createBunRedisClient for Bun's built-in Redis client.

maxRetriesPerRequest

This setting tells the ioredis client how many times to try a command that fails before throwing an error. So even though Redis is not reachable or offline, the command will be retried until this situation changes or the maximum number of attempts is reached.

This guarantees that the workers will keep processing forever as long as there is a working connection. If you create an ioredis client manually, BullMQ will throw an exception if this setting is not set to null when it is passed into worker instances. When using another Redis client through an adapter, configure that client's retry and reconnect behavior according to its own documentation so that worker connections can keep retrying.

Queue

Also note that simple Queue instance used for managing the queue such as adding jobs, pausing, using getters, etc. usually has different requirements from the worker.

For example, say that you are adding jobs to a queue as the result of a call to an HTTP endpoint - producer service. The caller of this endpoint cannot wait forever if the connection to Redis happens to be down when this call is made. Therefore the maxRetriesPerRequest setting should either be left at its default (which currently is 20) or set it to another value, maybe 1 so that the user gets an error quickly and can retry later.

On the other hand, if you are adding jobs inside a Worker processor, this process is expected to happen in the background - consumer service. In this case you can share the same connection.

For more details, refer to the persistent connections page.

When using ioredis connections, be careful not to use the "keyPrefix" option in ioredis as this option is not compatible with BullMQ, which provides its own key prefixing mechanism by using prefix option.

If you can afford many connections, by all means just use them. Redis connections have quite low overhead, so you should not need to care about reusing connections unless your service provider imposes hard limitations.

Make sure that your redis instance has the setting

maxmemory-policy=noeviction

in order to avoid automatic removal of keys which would cause unexpected errors in BullMQ