Re: [squid-users] squid 3.2 cache mechanism - not working properly compare to 3.1 series

From: Ben <benjo11111_at_gmail.com>
Date: Thu, 25 Oct 2012 15:51:03 +0530

On 25-10-2012 14:49, Amos Jeffries wrote:
> On 25/10/2012 7:24 p.m., Ben wrote:
>>
>> Hi,
>>
>> I upgraded my squid boxes from 3.1 series to 3.2 series. I noticed
>> that 3.2 is not better then 3.1 while concerning with caching
>> capabilities.
>>
>> I checked for simple web site , which has jpg images and all. as web
>> site is standard and normal site. So squid must cache it contents. I
>> tried many times, but each time i saw TCP_MISS in access.log
>>
>> I checked for a site which is elitecore.com ( as example )
>>
>> redbot url: http://redbot.org/?descend=True&uri=http://elitecore.com -
>> it suggests that this site is cacheable.
>>
>> squid version : 3.2.3
>>
>> currently, there is no change in squid.conf. I am using default one
>> for testing purposes.
>>
>>
>> what could be problem with squid-3.2.3? Is there any changes required
>> for 3.2.3 configuration or any changes in caching mechanism for 3.2
>> series?
>
> Firstly, TCP_MISS does *not* mean anything about whether the response to
> a previous request or to the curent request was cached. All it means is
> the current request was not serviced by anything already existing in cache.
>
> Both the client request headers AND the cached response headers are
> taken into account when deciding whether a response can be served from
> cache. It is perfectly reasonable to get a log trace like this from a
> client requesting brand new object and rejecting anything that might be
> stale (max-age=0).
>
> Since the site uses User-Agent in its Vary: header it is perfectly
> possible that each client request has a different agent string and
> MISS'es the previously cached entry. Even one byte of change in the
> agent string will cause those objects to MISS.
> But since you said 3.1 was working okay it is probably not this issue
> which affects all caches.

For testing purpose, I open same site from same browser and again run
same process to check caching is happening or not.

>
>
> For more info on what 3.2.3 is caching you can log at debug level 11,3
> and get log about each response and whether it was determined cacheable.
> Look for "cacheableReply" and a YES/NO with explained reason.

I enabled debug_options 11,3. It shows request/response header with
meaningfull information but I could not find "cacheableReply",
mentioning one block of request/response from log as per 11,3 debug level.

---------
GET http://elitecore.com/images/body_bkgd.jpg HTTP/1.1^M
Host: elitecore.com^M
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101
Firefox/15.0.1^M
Accept: image/png,image/*;q=0.8,*/*;q=0.5^M
Accept-Language: en-us,en;q=0.5^M
Accept-Encoding: gzip, deflate^M
Proxy-Connection: keep-alive^M
Referer: http://elitecore.com/css/stylesheet.css^M
Cookie: __utma=25544809.1437989579.1351159439.1351159439.1351159439.1;
__utmb=25544809.4.10.1351159439; __utmc=25544809;
__utmz=25544809.1351159439.1
.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)^M
If-Modified-Since: Thu, 24 Sep 2009 06:16:20 GMT^M
If-None-Match: "4005f-56a5-4744cc51a1500"^M
Cache-Control: max-age=0^M
^M

----------
2012/10/25 15:45:32.794 kid1| httpStart: "GET
http://elitecore.com/images/body_bkgd.jpg"
2012/10/25 15:45:32.794 kid1| HTTP Server local=10.115.1.230:30562
remote=180.179.100.102:80 FD 35 flags=1
2012/10/25 15:45:32.794 kid1| HTTP Server REQUEST:
---------
GET /images/body_bkgd.jpg HTTP/1.1^M
Host: elitecore.com^M
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101
Firefox/15.0.1^M
Accept: image/png,image/*;q=0.8,*/*;q=0.5^M
Accept-Language: en-us,en;q=0.5^M
Accept-Encoding: gzip, deflate^M
Referer: http://elitecore.com/css/stylesheet.css^M
Cookie: __utma=25544809.1437989579.1351159439.1351159439.1351159439.1;
__utmb=25544809.4.10.1351159439; __utmc=25544809;
__utmz=25544809.1351159439.1
.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)^M
If-Modified-Since: Thu, 24 Sep 2009 06:16:20 GMT^M
If-None-Match: "4005f-56a5-4744cc51a1500"^M
Via: 1.1 ns1.example.com (squid/3.2.3)^M
X-Forwarded-For: 10.115.1.16^M
Cache-Control: max-age=0^M
Connection: keep-alive^M

As per my understanding, In request header,I can see Cache-Control:
max-age=0 , so i add override-expire options with refresh_pattern to
cross this header parameters but still same.

refresh_pattern is for response header ? or for both request/response?
I added refresh_pattern,

refresh_pattern -i \.(jpg|jpeg)$ 1440 40% 14400 override-expire
for testing purpose .

How to cache such site's contents?

BR
Ben

>
>
> Amos
>
>>
>> I tested same site with 3.1. series and it is working fine.
>>
>> access.log :
>>
>> 1351098321.835 80 192.168.1.23 TCP_MISS/200 3414 GET
>> http://elitecore.com/ - HIER_DIRECT/180.179.100.102 text/html
>> 1351098321.876 19 192.168.1.23 TCP_MISS/200 1280 GET
>> http://elitecore.com/css/stylesheet.css - HIER_DIRECT/180.179.100.102
>> text/css
>> 1351098321.898 37 192.168.1.23 TCP_MISS/200 1352 GET
>> http://elitecore.com/js/menu.js - HIER_DIRECT/180.179.100.102
>> application/javascript
>> 1351098321.899 21 192.168.1.23 TCP_MISS/200 421 GET
>> http://elitecore.com/images/aarow_bullet.gif -
>> HIER_DIRECT/180.179.100.102 image/gif
>> 1351098321.913 52 192.168.1.23 TCP_MISS/200 3682 GET
>> http://elitecore.com/js/menuscript.js - HIER_DIRECT/180.179.100.102
>> application/javascript
>> 1351098321.919 57 192.168.1.23 TCP_MISS/200 5755 GET
>> http://elitecore.com/images/header_curve.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098321.919 57 192.168.1.23 TCP_MISS/200 9629 GET
>> http://elitecore.com/images/elitecore_logo.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098321.922 22 192.168.1.23 TCP_MISS/200 1156 GET
>> http://elitecore.com/images/home-mod-bot.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098321.941 1 192.168.1.23 TCP_MEM_HIT/200 33122 GET
>> http://meltwaternews.com/magenta/xml/html/51/05/v2_374671.html -
>> HIER_NONE/- text/html
>> 1351098321.973 1 192.168.1.23 TCP_MEM_HIT/200 57559 GET
>> http://meltwaternews.com/js/jquery_1.3.js - HIER_NONE/-
>> application/javascript
>> 1351098322.019 0 192.168.1.23 TCP_MEM_HIT/200 906 GET
>> http://meltwaternews.com/ext/a3logics/APAC/Images/FBN-32333bg1.png -
>> HIER_NONE/- image/png
>> 1351098322.145 247 192.168.1.23 TCP_MISS/200 5305 GET
>> http://elitecore.com/images/Telecommunication-icon.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098322.365 446 192.168.1.23 TCP_MISS/200 7354 GET
>> http://elitecore.com/images/AccessGateway-icon.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098322.575 662 192.168.1.23 TCP_MISS/200 6562 GET
>> http://elitecore.com/images/NetworkSecurity-icon.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098322.584 437 192.168.1.23 TCP_MISS/200 5460 GET
>> http://elitecore.com/images/menu_bkgd.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098322.865 498 192.168.1.23 TCP_MISS/200 5487 GET
>> http://elitecore.com/images/flyout_bkgd.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098323.379 514 192.168.1.23 TCP_MISS/200 5482 GET
>> http://elitecore.com/images/footer_bkgd.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098323.635 1710 192.168.1.23 TCP_MISS/200 5919 GET
>> http://elitecore.com/images/body_bkgd.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098324.097 2235 192.168.1.23 TCP_MISS/200 38616 GET
>> http://elitecore.com/images/home_banner_new.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098325.362 2786 192.168.1.23 TCP_MISS/200 441 GET
>> http://elitecore.com/images/home-mod-top-rep.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098325.765 3826 192.168.1.23 TCP_MISS/200 15368 GET
>> http://www.google-analytics.com/ga.js - HIER_DIRECT/173.194.36.36
>> text/javascript
>> 1351098325.861 3276 192.168.1.23 TCP_MISS/200 518 GET
>> http://elitecore.com/images/homepage-mod-top2.jpg -
>> HIER_DIRECT/180.179.100.102 image/jpeg
>> 1351098326.073 4153 192.168.1.23 TCP_MISS/200 46409 GET
>> http://elitecore.com/images/customers-new.gif -
>> HIER_DIRECT/180.179.100.102 image/gif
>> 1351098326.676 865 192.168.1.23 TCP_MISS/200 432 GET
>> http://www.google-analytics.com/__utm.gif? - HIER_DIRECT/173.194.36.36
>> image/gif
>> 1351098328.980 2291 192.168.1.23 TCP_MISS/200 21700 GET
>> http://elitecore.com/favicon.ico - HIER_DIRECT/180.179.100.102
>> image/x-icon
>>
>>
>> BR
>> Ben
>>
>>
>>
>
Received on Thu Oct 25 2012 - 10:23:48 MDT

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