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

[Amos Jeffries]

On 27/01/2017 9:46 a.m., Yuri Voinov wrote:
> 
> 
> 27.01.2017 2:44, Matus UHLAR - fantomas пишет:
>>> 26.01.2017 2:22, boruc пишет:
>>>> After a little bit of analyzing requests and responses with WireShark I
>>>> noticed that many sites that weren't cached had different
>>>> combination of
>>>> below parameters:
>>>>
>>>> Cache-Control: no-cache, no-store, must-revalidate, post-check,
>>>> pre-check,
>>>> private, public, max-age, public
>>>> Pragma: no-cache
>>
>> On 26.01.17 02:44, Yuri Voinov wrote:
>>> If the webmaster has done this - he had good reason to. Trying to break
>>> the RFC in this way, you break the Internet.
>>
>> Actually, no. If the webmaster has done the above - he has no damn
>> idea what
>> those mean (private and public?) , and how to provide properly cacheable
>> content.
> It was sarcasm.


You may have intended it to be. But you spoke the simple truth.

Other than 'public' there really are situations which have "good reason"
to send that set of controls all at once.

For example; any admin who wants a RESTful or SaaS application to
actually work for all their potential customers.


I have been watching the below cycle take place for the past 20 years in
HTTP:

Webmaster: dont cache this please.

  "Cache-Control: no-store"

Proxy Admin: ignore-no-store


Webmaster: I meant it. Dont deliver anything you cached without fetching
a updated version.

  ... "no-store, no-cache"

Proxy Admin: ignore-no-cache


Webmaster: really you MUST revalidate before using ths data.

 ... "no-store, no-cache, must-revalidate"

Proxy Admin: ignore-must-revalidate


Webmaster: Really I meant it. This is non-storable PRIVATE DATA!

... "no-store, no-cache, must-revalidate, private"

Proxy Admin: ignore-private


Webmaster: Seriously. I'm changing it on EVERY request! dont store it.

... "no-store, no-cache, must-revalidate, private, max-age=0"
"Expires: -1"

Proxy Admin: ignore-expires


Webmaster: are you one of those dumb HTTP/1.0 proxies who dont
understand Cache-Control?

"Pragma: no-cache"
"Expires: 1 Jan 1970"

Proxy Admin: hehe! I already ignore-no-cache ignore-expires


Webmaster: F*U!  May your clients batch up their traffic to slam you
with it all at once!

... "no-store, no-cache, must-revalidate, private, max-age=0,
pre-check=1, post-check=1"


Proxy Admin: My bandwidth! I need to cache more!

Webmaster: Doh! Oh well, so I have to write my application to force new
content then.

Proxy Admin: ignore-reload


Webmaster: Now What? Oh HTTPS wont have any damn proxies in the way....

... the cycle repeats again within HTTPS. Took all of 5 years this time.

... the cycle repeats again within SPDY. That took only ~1 year.

... the cycle repeats again within CoAP. The standards are not even
finished yet and its underway.


Stop this cycle of stupidity. It really HAS "broken the Internet".


HTH
Amos