[PATCH 2 of 2] Cache: send conditional requests only for cached 200 OK responses

[Maxim Dounin]

Hello!

On Tue, Nov 18, 2014 at 05:15:49PM -0800, Piotr Sikora wrote:

> # HG changeset patch
> # User Piotr Sikora <piotr at cloudflare.com>
> # Date 1416359233 28800
> #      Tue Nov 18 17:07:13 2014 -0800
> # Node ID 16f4ca8391ddd98ba99b00a46c0b56390f38e0a2
> # Parent  99e65578bc80960b2fdf494e048678dd97bba029
> Cache: send conditional requests only for cached 200 OK responses.
> 
> RFC7232 says:
> 
>    The 304 (Not Modified) status code indicates that a conditional GET
>    or HEAD request has been received and would have resulted in a 200
>    (OK) response if it were not for the fact that the condition
>    evaluated to false.
> 
> which means that there is no reason to send requests with "If-None-Match"
> and/or "If-Modified-Since" headers for responses cached with other status
> codes.
> 
> Also, sending conditional requests for responses cached with other status
> codes could result in a strange behavior, e.g. upstream server returning
> 304 Not Modified for cached 404 Not Found responses, etc.

And what's wrong with it?
I don't see why this should be status-specific.

-- 
Maxim Dounin
http://nginx.org/