Re: HAProxy, Set-Cookie and Cacheable Elements

Hi,

Why do you want to persist a cachable request to a backend server?

I use "cookie PHPSESSID prefix" to persist users only when needed. (if they got a session from logging in)

Karsten

Am Mittwoch, 28. April 2010 schrieb John Marrett:
> I've noticed some interesting behaviour with persistance cookies and
> haproxy.
>
> Let's say you use the following settings in your haproxy.cfg:
>
> cookie SERVERID insert indirect
> server static1 172.25.0.10:1080 cookie server1 check inter 15s
> server static2 172.25.0.11:1080 cookie server2 check inter 15s
>
> Any time haproxy receives a request that has no SERVERID cookie it will
> set one. Unfortunately, this doesn't take into consideration the
> cachability of the request. If a user receives a set-cookie in their
> response, on cacheable content, and if the proxy server isn't configured
> to strip Set-Cookie responses when serving from cache, all users of that
> proxy server will persist to a single backend server.
>
> I noticed this while looking into some other issues we were having with
> Set-Cookie and proxy servers (notably the great firewall of Singapore).
>
> Within our own application we either set Cache-Control: Private or
> ensure that we don't send a Set-Cookie on content that is declared as
> cacheable. I don't know if this kind of functionality could be
> interested for haproxy, but I thought I'd share my findings and see if
> anyone else was aware of this pattern of behaviour, if it was causing
> issues, and if there is or should be a way to address this issue.
>
> -JohnF
>
Received on 2010/04/29 08:38