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Re: Our old friends, weak ETags

From: Julian Reschke <julian.reschke@gmx.de>
Date: Tue, 24 Jul 2012 09:27:11 +0200
Message-ID: <500E4E4F.5000604@gmx.de>
To: Amos Jeffries <squid3@treenet.co.nz>
CC: ietf-http-wg@w3.org
On 2012-07-24 09:11, Amos Jeffries wrote:
> On 24/07/2012 6:39 p.m., Eric J. Bowman wrote:
>> "Adrien W. de Croy" wrote:
>>> a) does anyone actually use them?
>>>
>> Yes.
>>
>>> b) do they work?
>>>
>> I've never heard that they don't, nor run into any problems using them.
>>
>>> c) do we still need them?
>>>
>> Yes, otherwise I have to cache-expire for all changes to resource state,
>> without the option to declare certain changes insignificant.  Take a
>> "weblog entry" resource which includes a # of comments counter, with a
>> link to a comment thread.  XHR is used to synch the count, eventually.
>
> What type of server do you have which does not send strong ETag on
> binary-level changes anyway?
> ...

As far as I recall, Apache httpd/moddav sends a (timestamp-based) weak 
etag in PUT responses if it doesn't have sufficient time resolution. 
Once the change time for the underlying object is in the past, the ETag 
changes to a strong one.

Best regards, Julian
Received on Tuesday, 24 July 2012 07:27:47 GMT

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