# X-Sendfile

The `Send` HTTP middleware and the `X-Sendfile` HTTP response header are used to stream large files using RoadRunner. While the file is being streamed with the help of RoadRunner, the PHP worker may accept the next request.

Original issue: [link](https://github.com/roadrunner-server/roadrunner-plugins/issues/9) The middleware reads the file in 10 MB chunks. For example, for a 5 GB file, only 10 MB of RSS memory is used. If the file is smaller than 10 MB, the middleware adjusts the buffer to fit the file size.

## Similar approaches

* [NGINX](https://www.nginx.com/resources/wiki/start/topics/examples/xsendfile/)
* [Apache2](https://tn123.org/mod_xsendfile/)

## Configuration

{% code title=".rr.yaml" %}

```yaml
version: "3"

http:
  address: 127.0.0.1:55555
  max_request_size: 1024
  access_logs: false
  middleware: [ "sendfile" ]

  pool:
    num_workers: 2
    max_jobs: 0
    allocate_timeout: 60s
    destroy_timeout: 60s
```

{% endcode %}


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