How do I implement the "if modified since" header in drupal? I just read about it and apparently
it can save a great deal of bandwidth.

Cheers!

Max

Comments

gerd riesselmann’s picture

Drupal supports "if-modified-since". However, it is only used, when caching is enabled (so Drupal can determine the time of last change).

Drupal also support gzip-encoding when caching is enabled - this will even save you more bandwith :-). Note that PHP must be compiled with the "with-zlib" option to actually use this feature: http://php.net/manual/en/ref.zlib.php

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Gerd Riesselmann
www.gerd-riesselmann.net

giorgosk’s picture

(not all drupal nodes get gzipped which I don't really understand - root node / gets gzipped but /tracker does not ??)

but I don't know about 304 not modified headers.
I am using HTTP Debugger from softx.org to see the request and responses to servers
using IE6 and FF1.5.0.2 and I don't see any 304 not modifiled for the actual nodes but only for the resources (.js .css .png .jpg) but I am not sure that this is actually drupal
doing it. I think its the apache server right ?

--
chios sightseeings

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GiorgosK
Web Development

gerd riesselmann’s picture

Yes, ressources (*.js, *.png etc.) are handled by Apache itself.

Using Firefox's LiveHeader extension, I had a look at the headers send when refreshing content on a local site, and a 304 gets send as it should be.

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Gerd Riesselmann
www.gerd-riesselmann.net