On 9/01/2013 9:43 p.m., Victor wrote:
Hello
After spending hours configuring squid 3.2.5, I only get TCP_MISS. To
narrow the problem, I will focus on one PNG file that I want cached, but
note that I get TCP_MISS for 99% of my requests, not only PNG files.
Refreshing doesn’t help, it never gets a TCP_HIT.
1357671721.566 127 127.0.0.1 TCP_MISS/200 618 GET
http://flags.tatoeba.org/img/flags/epo.png - HIER_DIRECT/86.65.39.22
image/png
in cache.log, I get:
<snip>
2013/01/09 09:27:04.757 kid1| http.cc(732) processReplyHeader:
HTTP Server local=192.168.1.13:56799 remote=86.65.39.22:80 FD 13
flags=1
2013/01/09 09:27:04.757 kid1| http.cc(733) processReplyHeader:
HTTP Server REPLY:
---------
HTTP/1.1 200 OK
Date: Wed, 09 Jan 2013 08:27:24 GMT
Server: Apache/2.2.16 (Debian)
Accept-Ranges: bytes
Content-Length: 219
Vary: User-Agent
Expires: Fri, 10 Jan 2014 00:00:00 GMT
Cache-Control: public, no-transform
Content-Type: image/png
Via: 1.1 tatoeba.fsffrance.org
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
�PNG
This particular object is likely a MISS because it says Vary:User-Agent.
This is a rather unfriendly action for a site to take, it means that
even a single byte of diffference in two clients User-Agent header cause
a MISS and replaces the cached content with new data (which will likely
MISS on the next client too).
And this is my config file:
cache_effective_user squid
cache_effective_group squid
acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC1918 possible internal
network
acl localnet src 192.168.0.0/16 # RFC1918 possible internal
network
acl localnet src fc00::/7 # RFC 4193 local private network range
acl localnet src fe80::/10 # RFC 4291 link-local (directly
plugged) machines
acl SSL_ports port 443
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 # https
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl Safe_ports port 901 # SWAT
acl CONNECT method CONNECT
http_access allow localhost manager
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
debug_options ALL,1 11,3 31,3 65,3
http_access allow localnet
http_access allow localhost
http_access deny all
http_port 3303
cache_dir ufs /var/cache/squid 600 16 256
cache_mem 256 MB
coredump_dir /var/cache/squid
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern -i \.(gif|png|jpg|jpeg|ico|bmp)$ 260000 90%
260009 override-expire ignore-no-cache ignore-no-store
ignore-private
In 3.2 "ignore-no-cache" is now ignored. The Cache-Control:no-cache
header *actually* tells Squid to revalidate the object before sending
(this MAY result in a MISS if the object has changed, or in a REFRESH /
304 status if the server object has not).
override-expires tells Squid to ignore the Expires header, in the object
in your log above Expires is the only thing provided to Squid indicating
that the objet is storable. Ignoring it may lead to MISS for objects
without Cache-Control which rely on it for storage timing (like the PNG
above does).
ignore-private - this is a very dangerous thing to do. Even things like
images may have drastic unwanted side effects. Think about security
Captcha systems ... what happens when you force serving the client a
cached image there? Just about every file type has some problem when you
generalize it across the entire Internet. If you have to use this
directive at all make the pattern as specific as possible to the problem
case.
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320
Note that I doubled check that my cache directories belonged to
squid:squid and their size slowly grows when I am using squid, yet I get
a TON of tcp_miss, even on cacheable sites (such aswww.lci.fr)
Any idea?
Okay. So the objects are being cached, but not served from there.
In 3.2.5 debug_options 22,3 should give you the stale.fresh outcomes
from the cache check.
Amos
