Norbert Hoeller wrote:
Although my squid server is only supporting three users, I am pleasantly
surprised at the percentage of traffic handled by the cache. However, I think
I can do better. Scanning the logs, I noticed a number of cases where the same
files were resulting in a TCP_MISS/200 condition. A lot are due to '?'-strings
in the URL, even though the content is not always dynamic (I am researching
options).
Making sure you don't have...
acl QUERY urlpath_regex cgi-bin \?
cache deny QUERY
...in your squid.conf, in conjunction with the refresh_patterns you DO
have are about as far as you can go without starting to break standards.
However, I see a fair number of cases where I would expect the object to be
cached. Is there a process for diagnosing why squid thinks the object is not
cache-able?
Up the debug_options for 22 and maybe 65. See
http://wiki.squid-cache.org/KnowledgeBase/DebugSections for a list.
For example, from the access.log and store.log files:
1265776256.982 3934 10.1.2.123 TCP_MISS/200 861 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif -
DIRECT/66.220.146.18 image/gif
1265776281.912 370 10.1.2.123 TCP_MISS/200 861 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif -
DIRECT/66.220.146.18 image/gif
1265776294.352 407 10.1.2.123 TCP_MISS/200 861 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif -
DIRECT/66.220.146.18 image/gif
1265776256.982 RELEASE -1 FFFFFFFF 54F74EF7200473A70B1E94F452E355C0 200
-1 -1 1265776256 image/gif 522/522 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif
1265776281.912 RELEASE -1 FFFFFFFF D50A66A7F3C5E849631BF132637A99A3 200
-1 -1 1265776281 image/gif 522/522 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif
1265776294.352 RELEASE -1 FFFFFFFF 25AA53B40429083AF5B68BAF4A663EF0 200
-1 -1 1265776294 image/gif 522/522 GET
http://www.facebook.com/images/loaders/indicator_blue_small.gif
redbot.org returns:
HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=2592000
Content-Type: image/gif
Expires: Sat, 13 Mar 10 22:37:08 GMT
X-Cnection: close
Date: Thu, 11 Feb 2010 22:37:08 GMT
Content-Length: 522
General: The Expires header's value isn't a valid date.The Content-Length
header is correct.The server's clock is correct.
Caching: This response can be stored by any cache.This response is fresh until
4 weeks 2 days from now.This response can be served stale.
Partial Content: A ranged request returned the full rather than partial content
I am using a fairly vanilla squid.conf file, with the exception of some
ad-blocking:
#Suggested default:
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern (cgi-bin|\?) 0 0% 0
refresh_pattern . 0 20% 4320
Any suggestions would be greatly appreciated!
Thanks, Norbert
Chris
