---
title: Additional Networking Settings
hide_title: true
sidebar_position: 4
version: 1
---

## Additional Networking Settings

### CORS

To configure CORS, or cross-origin resource sharing, the following dependency must be installed:

```python
pip install apache-superset[cors]
```

The following keys in `superset_config.py` can be specified to configure CORS:

- `ENABLE_CORS`: Must be set to `True` in order to enable CORS
- `CORS_OPTIONS`: options passed to Flask-CORS
  ([documentation](https://flask-cors.corydolphin.com/en/latest/api.html#extension))

### Domain Sharding

Chrome allows up to 6 open connections per domain at a time. When there are more than 6 slices in
dashboard, a lot of time fetch requests are queued up and wait for next available socket.
[PR 5039](https://github.com/apache/superset/pull/5039) adds domain sharding to Superset,
and this feature will be enabled by configuration only (by default Superset doesn’t allow
cross-domain request).

Add the following setting in your `superset_config.py` file:

- `SUPERSET_WEBSERVER_DOMAINS`: list of allowed hostnames for domain sharding feature.

### Middleware

Superset allows you to add your own middleware. To add your own middleware, update the
`ADDITIONAL_MIDDLEWARE` key in your `superset_config.py`. `ADDITIONAL_MIDDLEWARE` should be a list
of your additional middleware classes.

For example, to use `AUTH_REMOTE_USER` from behind a proxy server like nginx, you have to add a
simple middleware class to add the value of `HTTP_X_PROXY_REMOTE_USER` (or any other custom header
from the proxy) to Gunicorn’s `REMOTE_USER` environment variable: