Question about ETag header?

Aleksandar Lazic al-nginx at
Sat Dec 16 21:14:00 MSK 2006

On Sam 16.12.2006 10:27, Igor Sysoev wrote:
>On Fri, 15 Dec 2006, Aleksandar Lazic wrote:
>>I'am not sure if it's good or bad also how helpfull it really is,
>>maybe someone on the list could help to understand this ;-)?!
>I saw that browsers and cache proxies use Last-Modified as tag but not
>as time value. If they want to revalidate response, they send
>If-Modified-Since with the same value as they have received. MSIE adds
>", length=XXXX" string.  nginx gets time in seconds from IMS header and
>does IMS == LM comparsion, but not "IMS <= LM" comparsion to return

Sorry but, the ETag is a addon for the LM and IMS as I have right
understand the rfc2616.

I'am still reading it but it isn't so easy :-/

>>Btw.: How is the entity value calculated?!
>Now Apache use "FileETag INode MTime Size" directive. Before Apache
>1.3.23 the ETag was always formed as "inode-size-mtime" and the same
>files from mirror image servers have the different ETags.

Thanks for explanation.



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