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

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 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.

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 - 09:19:33 MDT