> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/taskforcesh/bullmq/llms.txt
> Use this file to discover all available pages before exploring further.

# Redis Cluster

> Configure BullMQ to work with Redis Cluster using hash tags

Bull internals require atomic operations that span different keys. This behavior breaks Redis's rules for cluster configurations. However, it is still possible to use a cluster environment by using the proper bull prefix option as a cluster "hash tag".

## What are Hash Tags?

Hash tags are used to guarantee that certain keys are placed in the same hash slot. A hash tag is defined with brackets. A key that has a substring inside brackets will use that substring to determine in which hash slot the key will be placed.

Read more about hash tags in the [Redis cluster tutorial](https://redis.io/topics/cluster-tutorial).

## Configuration Options

You can use two approaches to make the Queues compatible with Cluster:

### Option 1: Queue Prefix

Define a queue prefix wrapped in brackets:

```typescript theme={null}
const queue = new Queue('cluster', {
  prefix: '{myprefix}',
});
```

### Option 2: Queue Name

Wrap the queue name itself in brackets:

```typescript theme={null}
const queue = new Queue('{cluster}');
```

## Multiple Queues

<Warning>
  If you use several queues in the same cluster, you should use different prefixes so that the queues are evenly placed in the cluster nodes, potentially increasing performance and memory usage.
</Warning>

```typescript theme={null}
// Good: Different prefixes for load distribution
const emailQueue = new Queue('emails', { prefix: '{emails}' });
const videoQueue = new Queue('videos', { prefix: '{videos}' });
const imageQueue = new Queue('images', { prefix: '{images}' });

// Bad: Same prefix causes all queues to be on same node
const emailQueue = new Queue('emails', { prefix: '{myapp}' });
const videoQueue = new Queue('videos', { prefix: '{myapp}' });
const imageQueue = new Queue('images', { prefix: '{myapp}' });
```

## Connecting to Redis Cluster

Use ioredis Cluster connection:

```typescript theme={null}
import { Queue } from 'bullmq';
import Redis from 'ioredis';

const cluster = new Redis.Cluster([
  {
    port: 6380,
    host: '127.0.0.1',
  },
  {
    port: 6381,
    host: '127.0.0.1',
  },
]);

const queue = new Queue('{myqueue}', {
  connection: cluster,
});
```

## Workers and QueueEvents

The same prefix rules apply to Workers and QueueEvents:

```typescript theme={null}
const worker = new Worker(
  '{myqueue}',
  async job => {
    // Process job
  },
  { connection: cluster },
);

const queueEvents = new QueueEvents('{myqueue}', {
  connection: cluster,
});
```

## Best Practices

<Steps>
  <Step title="Use Hash Tags">
    Always wrap queue names or prefixes in brackets for cluster compatibility
  </Step>

  <Step title="Distribute Load">
    Use different prefixes for different queues to spread load across cluster nodes
  </Step>

  <Step title="Consistent Naming">
    Use the same prefix across Queue, Worker, and QueueEvents for the same queue
  </Step>

  <Step title="Test Failover">
    Test your setup with node failures to ensure proper cluster behavior
  </Step>
</Steps>

## Related Resources

<CardGroup cols={2}>
  <Card title="Connections" icon="link" href="/concepts/connections">
    Learn about Redis connection configuration
  </Card>

  <Card title="Redis Compatibility" icon="server" href="/redis/compatibility">
    Redis version requirements and compatibility
  </Card>
</CardGroup>