> 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
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. |
---
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