Serving Authenticated Static Content was pretty expensive before today

It has always been the pain when we need to server authenticated static content. Because we are bound with programming framework to handle the authentication job. And once authenticated,

you have to read the file from the Disk through your programming to stream to the end user with correct mime type. This was the only solution for me before today.

While working on some project, i’ve found XSendfile and X-Accel. X-accel allows for internal redirection to a location determined by a header returned from a backend.

This allows you to handle authentication, logging or whatever else you please in your backend and then have NGINX handle serving the contents from redirected location to the end user, thus freeing up the backend to handle other requests. This feature is commonly known as X-Sendfile.

NGINX also has this feature, but implemented a little bit differently. In NGINX this feature is called X-Accel-Redirect.

There are two main differences:

1. The header must contain a URI.
2. The location should be defined as internal; to prevent the client from going directly to the URI.

We have been missing this feature in our elgg development. Now we will definitely use this module to get the better performance while service static content to the end user. No more stream reading from disk and serve further.