[squid-users] Re: squid reverse proxy caching session id?

Henrik Nordstrom wrote:
> On tis, 2007-08-21 at 15:43 +0800, solidzh wrote:
>
>
>> How to avoid squid cache this url which come with cookid?thanks.
>>
>
> The best way is to make sure the server sends "Cache-Control: private"
> on any user specific content, as required by the HTTP protocol standard.
>

Sorry, but this is not sufficient in general, as the Cache-Control
header is from HTTP 1.1, and caches that follow the older standard HTTP
1.0 will not understand it. Since the only caching directive such
caches understand is the Expires: timestamp, you must add such a
timestamp as well:

    Cache-Control: private
    Expires: Mon, 01 Jan 2007 00:00:00 GMT

Generally, any Expires: timestamp in the past will prevent caching. It
is not possible in general to express all the fancy caching directives
of HTTP 1.1 in HTTP 1.0, and to preserve correctness, the Expires:
header must be so restrictive that no unwanted caching by HTTP 1.0
caches can occur. This may hurt performance, but that is better than
wrong results.

Regards,

Oliver Schoett
Received on Fri Jan 11 2008 - 10:10:21 MST