launchpad-dev team mailing list archive

[Martin Pool <mbp@xxxxxxxxxxxxx>]

On 12 November 2010 08:09, Robert Collins <robert.collins@xxxxxxxxxxxxx> wrote:
> On Fri, Nov 12, 2010 at 9:50 AM, Michael Hudson
> <michael.hudson@xxxxxxxxxxxxx> wrote:
>> On Thu, 11 Nov 2010 15:44:50 +1300, Robert Collins <robertc@xxxxxxxxxxxxxxxxx> wrote:
>>> On Thu, Nov 11, 2010 at 3:27 PM, Michael Hudson
>>> <michael.hudson@xxxxxxxxxxxxx> wrote:
>>> > A problem with etag is that squid doesn't pay any attention to it. Â But
>>> > it will help browsers, I'm sure :-)
>>>
>>> ?!
>>
>> Well, I'm probably simplifying grossly.  What I wanted to happen was
>> that if you have a squid in front of loggerhead that if a request comes
>> in from the internet for a page (with no If-None-Match header) and squid
>> has the page cached, that squid would check the validity of the cache by
>> making a request to loggerhead with an If-None-Match and if that
>> returned 304, squid should return the page from its cache.  I couldn't
>> get this to happen.  My understanding was that mod_disk_cache would do
>> this.
>>
>> It was quite a while ago, I've forgotten details and was quite probably
>> mistaken even at the time...
>
> 2001-05-30 If-None-Match etag queries
> On cache misses for varying object If-None-Match is now used to query
> the origin server which (if any) of the caced entities matches the
> request.
> 2001-05-30 If-None-Match cache validation
> If-None-Match is now used on cache validations, using the entity tag
> of the exact object being validated. This ensures that even sub-second
> updates are detected properly, and cache validation is now less time
> sensitive.
>
> its done it for a long time :)
>
> -Rob


(Please keep Max cc'd, I'm not sure if he's on the lp-dev list.)

There is a bug <http://pad.lv/248901> about this, with some history
including mwh's research, and previous problems in getting squid to do
what was wanted.

-- 
Martin