Re: [squid-users] An example to squid cache affecting user-agents(Firefox,Chrome,wget\curl)

From: Eliezer Croitoru <eliezer_at_ngtech.co.il>
Date: Thu, 11 Jul 2013 18:20:49 +0300

On 07/11/2013 05:03 PM, Amos Jeffries wrote:
> On 11/07/2013 11:40 p.m., Eliezer Croitoru wrote:
>> I have been testing quite some time some urls for cachability.
>> It seems like there are different methods to request the same file which
>> leads to different reaction in squid and I want to make sure 100% what
>> is the cause to the *problem* before I am running to a conclusion since
>> I am not 100% sure.
>> Please take your *free* time to read it and see if there is something I
>> probably missed with hope to understand the issue in hands.\
>
> As you probably noticed from the final diagnois of the last weird case
> you brought up it can be important to consider both pairs of
> request/reply between both client-squid and squid-server. Either side of
> Squid can affect the overall transaction behaviour...
>
> Can you state exactly what the problem is up front? that is a little
> unclear from your text.
Sorry about it.
The problem is that admins and me analyse the access.log and consider a
X_HIT response to be a valid HIT response.
I think that the way cache admin analyse the log and understand what the
log means is different from admin to admin.
I wanted to explain in a more detailed way the logic I was explaining
before but since I am not always full of words about it I can describe
it in couple ways and not touch the other admin.

I wanted to make sure that:
1. there is or there isn't a bug related to Vary headers.
2. make sure I understand where in plain view without digging into the
code I understand the bugs and squid behaviour.
3. not just talk without a more detailed debug logs.
4. prove\show squid 3.2\3 changes that you have mentioned about the
no-cache directive which should be documented in a more detailed way.
Since admins dosn't understand it in many cases like I wasn't sure and
pretty confused about it I believe that it helped and will help others
understand the issue.

I think that now that the ignore-no-cache was removed there is might be
a need to add a Warning message while parsing squid.conf that will tell
admins about the new behaviour of refresh_pattern.
There is the "Removed option ignore-no-cache. Its commonly desired
behaviour is obsoleted by correct HTTP/1.1 Cache-Control:no-cache handling."

But It took me pretty while to actually notice it was there and
understand the meaning of it.

What do you think Amos?
(Sorry that I cannot send a patch proposal for that now)

Eliezer
Received on Thu Jul 11 2013 - 15:21:10 MDT

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