Re: [squid-users] refresh_pattern configuration

Muhammad Sharfuddin wrote:
> On Sun, 2009-08-09 at 14:19 +1200, Amos Jeffries wrote:
>> Muhammad Sharfuddin wrote:
>>> Squid Cache: Version 2.5.STABLE12
>>> and
>>> Squid Cache: Version 2.7.STABLE5
>>>
>>> I am using following refresh_patterns and never encounter any problem.
>>> e.g once I visit a website, on next visit usually squid serves it from
>>> cache, and TCP_HIT or TCP_MEM_HIT or TCP_REFRESH_HIT etc are so common
>>> in '/var/log/squid/access'
>>>
>>> But a person(who I beleive is a Linux/Squid Guru) critcize on the
>>> refresh_pattern I am using in squid.
>> (One of my posts or someone else?).
>>
>>> So please pass your comments and corrections on the following configs
>>>
>>> #Suggested default:
>>> refresh_pattern ^ftp: 1440 20% 10080
>>> refresh_pattern ^gopher: 1440 0% 1440
>>> ####refresh_pattern . 0 20% 4320
>>>
>>> refresh_pattern -i \.ico$ 43200 100% 43200 override-lastmod
>>> override-expire ignore-reload
>> The problem with these commonly used patterns is that websites are now
>> obfuscating the URL with query strings more and more often. Not always
>> intentionally.
>>
>> Example; the above pattern will not match any website with:
>> http://example.com/some.ico?sid=user-session-id&track=fukn-cookie-id
>>
>> changing the hard $ to softer (\?.*)?$ catches all of those websites
>> and keeps Squid doing what you meant to configure.
>>
>>
>> Other than that the only thing to draw real criticism is the use of
>> non-compliant override options. It's not nice netizen behaviour, ... but
>> ... "everyone else does it".
>>
>>
>> [warning rant ahead: (not your fault I know)]
>>
>> Personally as a webmaster I set realistic expiry info on every website I
>> touch in order to maximize speed and cacheability, particularly since
>> getting to now Squid. It really annoys me that admin like yourself are
>> forced to do this by a horribly large amount of clueless websites and
>> CMS software developers.
>> Such rules will in fact _decrease_ the cacheability times and benefits
>> for many of the websites I and other clued-on people setup. We are
>> forced to cope by changing filenames and sometimes URL links on every
>> single edit, no matter how trivial.
>> I'm sick of people complaining "why can Y see their user icon in forum X
>> but I can't? ... what?! cant fix it till next month just because I live
>> in country/ISP X?" always the webmaster to blame, never the browser
>> author or transparent proxy admin.
>> /rant
>>
>> Amos
>
> So in other words its not a healthy practice to use 'refresh_patterns'
> other then the defaults(in squid.conf 'Suggested default') ?.

The patterns and min/pct/max settings are fine. They do help.
It's the optional extensions ignore-* and override-* which break HTTP
and cause issues.

Amos

-- 
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