[squid-users] Not all html objects are being cached

[Garri Djavadyan]

On Fri, 2017-01-27 at 06:15 -0800, joseph wrote:
> hi its not about https scheme its about evrything

Hi,

First of all, I can't brag about my English and writing style, but your
writing style is _very_ offensive to other members. Please, try it
better. First of all, it is very difficult to catch the idea of many
sentences. I believe punctuation marks could help a lot. Thanks in
advance.

> i decide not to involve with arg...
> but why not its the last one i should say it once
> they ar right most of the ppl admin have no knwoleg so its ok to baby
> sit
> them as its
> but
> --enable-http-violations should be fully ignore cache control and in
> refresh
> pattern  admin shuld control the behavior of his need else they
> should  take
> of  —enable-http-violations or alow us to do so
> controlling the 
> Pragma: no-cache     and  Cache-Control: no-cache + + ++ +
> in both request reply

Squid, as HTTP/1.1 compliant cache successfully caches and serves
CC:no-cache replies. Below is excerpt from the RFC7234:

5.2.2.2.  no-cache

   The "no-cache" response directive indicates that the response MUST
   NOT be used to satisfy a subsequent request without successful
   validation on the origin server.

The key word is _validation_. There is nothing bad with revalidation.
It is inexpensive but saves us from possible problems. The log entry
'TCP_REFRESH_UNMODIFIED' should be welcomed as TCP_HIT or TCP_MEM_HIT.

Example:

$ curl -v -s -x http://127.0.0.1:3128 http://sandbox.comnet.local/test.
bin >/dev/null

< HTTP/1.1 200 OK
< Last-Modified: Wed, 31 Aug 2016 19:00:00 GMT
< Accept-Ranges: bytes
< Content-Length: 262146
< Content-Type: application/octet-stream
< Expires: Thu, 01 Dec 1994 16:00:00 GMT
< Date: Fri, 27 Jan 2017 14:55:09 GMT
< Server: Apache
< ETag: "ea0cd5-40002-53b62b438ac00"
< Cache-Control: no-cache
< Age: 3
< X-Cache: HIT from gentoo.comnet.uz
< Via: 1.1 gentoo.comnet.uz (squid/3.5.23-BZR)
< Connection: keep-alive

1485528912.222     18 127.0.0.1 TCP_REFRESH_UNMODIFIED/200 262565 GET h
ttp://sandbox.comnet.local/test.bin - HIER_DIRECT/192.168.24.5
application/octet-stream


As you can see, there are no problems with the no-cache reply.


I advise you to consider every specific case where you believe Squid's
transition to HTTP/1.1 compliance restricts you to cache something.


Garri