Maxim Dounin Wrote:
> This makes me think that it is just a cached 500 response from
> your backend then. If in doubt, you can obtain details using
> debug log, see http://wiki.nginx.org/Debugging.
>

I also considered that, but then I'd need to have at least hundreds of 500 status codes since other users are hitting the same page some seconds before or later. They get status code 200 though with a valid response. I even looked at the content of the cache file and it seemed ok.

Thanks for the link - I'll turn on debugging for the error log and see if I can find something.