Error Pages Cache

This article provides instructions on how to determine if a page is configured to be cached based on the response headers returned.

Caching Error Pages

Sometimes clients will notice that their error pages are being cached. Say one of their files was missing from the origin, and they re-uploaded it, but CDN is still returning their 404 page until the cache is fully purged. The reason behind this is that the 404 page happened to have a Cache-Control Header. In the example below, a 404 page with a CCH will be cached.

$ curl -I http://foobar.example.com/myimages/some_random_image.png
HTTP/1.1 404 Not Found
Server: nginx/1.0.11
Date: Thu, 26 Jan 2012 20:01:36 GMT
Content-Type: text/html;charset=utf-8
Connection: keep-alive
Cache-Control: public, max-age=24383317
Expires: Tue, 06 Dec 2012 17:33:42 GMT
Last-Modified: Sat, 01 Jan 2000 00:00:00 GMT
Content-Length: 1051

These bolded headers should not exist with error pages, otherwise, Nginx will cache the error page as if it is a valid page.

Please make sure to unset/remove all headers on your 404/Error pages. Or if not possible, set a no-cache header as explained below, and as explained in this article.

    ExpiresDefault A0
    Header set Cache-Control "no-store, no-cache, must-revalidate, max-age=0"
    Header set Pragma "no-cache"

If you have any questions or experience any issues, please reach out to the Support Team, live chat and ticket support are available 24/7.