---
#https://www.notion.so/n8n/Frontmatter-432c2b8dff1f43d4b1c8d20075510fe4
title: Queue mode environment variables
description: Environment variables to configure queue mode on your self-hosted n8n instance. 
contentType: reference
tags:
  - environment variables
hide:
  - toc
  - tags
---

# Queue mode environment variables

--8<-- "_snippets/self-hosting/file-based-configuration.md"

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

| Variable | Type  | Default  | Description |
| :------- | :---- | :------- | :---------- |
| `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.<br/><br/>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 | - | The port to serve health checks on. |
| `QUEUE_WORKER_LOCK_DURATION` | Number | `30000` | How long (in ms) is the lease period for a worker to work on a message. |
| `QUEUE_WORKER_LOCK_RENEW_TIME` | Number | `15000` | 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](/hosting/scaling/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. |