> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/deploy/host-n8n/configure-n8n/basic-configuration/use-environment-variables/queue-mode.md).

# Queue mode

{% hint style="info" %}
**File-based configuration**

You can add `_FILE` to individual variables to provide their configuration in a separate file. Refer to [Keeping sensitive data in separate files](/deploy/host-n8n/configure-n8n/basic-configuration.md#keeping-sensitive-data-in-separate-files) for more details.
{% endhint %}

You can run n8n in different modes depending on your needs. Queue mode provides the best scalability. Refer to [Queue mode](/deploy/host-n8n/configure-n8n/scaling/enable-queue-mode.md) for more information.

| Variable                                | Type    | Default     | Description                                                                                                                                                                                                                                                                                                                                       |
| --------------------------------------- | ------- | ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `OFFLOAD_MANUAL_EXECUTIONS_TO_WORKERS`  | Boolean | `false`     | Set to `true` if you want manual executions to run on the worker rather than on main.                                                                                                                                                                                                                                                             |
| `QUEUE_BULL_PREFIX`                     | String  | -           | Prefix to use for all queue keys.                                                                                                                                                                                                                                                                                                                 |
| `QUEUE_BULL_REDIS_DB`                   | Number  | `0`         | The Redis database used.                                                                                                                                                                                                                                                                                                                          |
| `QUEUE_BULL_REDIS_HOST`                 | String  | `localhost` | The Redis host.                                                                                                                                                                                                                                                                                                                                   |
| `QUEUE_BULL_REDIS_PORT`                 | Number  | `6379`      | The Redis port used.                                                                                                                                                                                                                                                                                                                              |
| `QUEUE_BULL_REDIS_USERNAME`             | String  | -           | The Redis username (needs Redis version 6 or above). Don't define it for Redis < 6 compatibility                                                                                                                                                                                                                                                  |
| `QUEUE_BULL_REDIS_PASSWORD`             | String  | -           | The Redis password.                                                                                                                                                                                                                                                                                                                               |
| `QUEUE_BULL_REDIS_TIMEOUT_THRESHOLD`    | Number  | `10000`     | The Redis timeout threshold (in ms).                                                                                                                                                                                                                                                                                                              |
| `QUEUE_BULL_REDIS_CLUSTER_NODES`        | String  | -           | Expects a comma-separated list of Redis Cluster nodes in the format `host:port`, for the Redis client to initially connect to. If running in queue mode (`EXECUTIONS_MODE = queue`), setting this variable will create a Redis Cluster client instead of a Redis client, and n8n will ignore `QUEUE_BULL_REDIS_HOST` and `QUEUE_BULL_REDIS_PORT`. |
| `QUEUE_BULL_REDIS_TLS`                  | Boolean | `false`     | Enable TLS on Redis connections.                                                                                                                                                                                                                                                                                                                  |
| `QUEUE_BULL_REDIS_DUALSTACK`            | Boolean | `false`     | Enable dual-stack support (IPv4 and IPv6) on Redis connections.                                                                                                                                                                                                                                                                                   |
| `QUEUE_WORKER_TIMEOUT` (**deprecated**) | Number  | `30`        | **Deprecated** Use `N8N_GRACEFUL_SHUTDOWN_TIMEOUT` instead. How long should n8n wait (seconds) for running executions before exiting worker process on shutdown.                                                                                                                                                                                  |
| `QUEUE_HEALTH_CHECK_ACTIVE`             | Boolean | `false`     | Whether to enable health checks (true) or disable (false).                                                                                                                                                                                                                                                                                        |
| `QUEUE_HEALTH_CHECK_PORT`               | Number  | `5678`      | The port to serve health checks on. If you experience a port conflict error when starting a worker server using its default port, change this.                                                                                                                                                                                                    |
| `QUEUE_WORKER_LOCK_DURATION`            | Number  | `60000`     | How long (in ms) is the lease period for a worker to work on a message.                                                                                                                                                                                                                                                                           |
| `QUEUE_WORKER_LOCK_RENEW_TIME`          | Number  | `10000`     | How frequently (in ms) should a worker renew the lease time.                                                                                                                                                                                                                                                                                      |
| `QUEUE_WORKER_STALLED_INTERVAL`         | Number  | `30000`     | How often should a worker check for stalled jobs (use 0 for never).                                                                                                                                                                                                                                                                               |
| `QUEUE_WORKER_MAX_STALLED_COUNT`        | Number  | `1`         | Maximum amount of times a stalled job will be re-processed.                                                                                                                                                                                                                                                                                       |

## Multi-main setup <a href="#multi-main-setup" id="multi-main-setup"></a>

Refer to [Configuring multi-main setup](/deploy/host-n8n/configure-n8n/scaling/enable-queue-mode.md#configuring-multi-main-setup) for details.

| Variable                              | Type    | Default | Description                                                           |
| ------------------------------------- | ------- | ------- | --------------------------------------------------------------------- |
| `N8N_MULTI_MAIN_SETUP_ENABLED`        | Boolean | `false` | Whether to enable multi-main setup for queue mode (license required). |
| `N8N_MULTI_MAIN_SETUP_KEY_TTL`        | Number  | `10`    | Time to live (in seconds) for leader key in multi-main setup.         |
| `N8N_MULTI_MAIN_SETUP_CHECK_INTERVAL` | Number  | `3`     | Interval (in seconds) for leader check in multi-main setup.           |