Richard Chapman wrote:
Amos Jeffries wrote:
Richard Chapman wrote:
I have a more or less default configured squid 2.6 proxy on a centos
5.4 server.
I have configured AVG 9 network edition (Virus scanner) to use the
squid proxy (as opposed to the avg proxy) - and it appears to be
doing so.
However - checking the usage logs - it appears that different client
machines download identical update (.bin) files within a few hours of
each other - but do not appear to get a cache hit..
Can anyone suggest why these update files are not being cached (or at
least not getting cache hits) - and whether there is anything I can
do to encourage them to be cached?
I have checked the Squid FAQ and searched the archive - and found a
similar request from 2005. The suggestion there was that the AVG
server might be using the
"Pragma: no-cache" HTTP header
To be sure take the URL that should be a HIT and enter it at redbot.org.
The whole problems should be easily visible there.
And that at that time there was no suggestion on how to override
this. Can anyone confirm that this is the reason for the apparently
unnecessary cache misses - and if so - is there anything new in squid
to allow us to override?
Squid which do not ignore "Pragma: no-cache" treat it the same as
"Cache-Control: no-cache"
Amos
Thanks Amos
I tried redbot as you suggested - and this is a url which I think SHOULD
have been a hit - though it is hard to be sure. The stats show that NONE
of the avg updates come from cache - and I assume they should all have
similar headers... Hopefully someone more knowledgeable than I can make
more sense of this;
http://redbot.org/?uri=http://aa.avg.com/softw/90/update/u7iavi2551u2550qp.bin
It looks to me that it should be cacheable - but the only suspicious
thing is the statement I get when I hover over the "This response is
stale". I think it says that it has a "Freshnes lifetime of 0" - which
sounds like it will always be considered stale. I'm not sure why they
would do this as each update has a unique file name - and could
therefore be considered fresh indefinitely couldn't it?
Can anyone confirm my interpretation - and/or suggest a way to treat the
updates more rationally?
Richard.
A cache considers a HTTP response stale when its age (here, 0) is equal
to or exceeds its freshness lifetime (in this case, 0)
A A cache considers a HTTP response stale when its age (here, 0) is
equal to or exceeds its freshness lifetime (in this case, 0).cache
considers a HTTP response stale when its age (here, 0) is equal to or
exceeds its freshness lifetime (in this case, 0).
Hmm, something strange there.
AFAIK the object looks like with the L-M header + the Date should have
both non-zero freshness (Date - LM) and an age (now - Date).
Amos
--
Please be using
Current Stable Squid 2.7.STABLE7 or 3.0.STABLE20
Current Beta Squid 3.1.0.15
