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Re: Http overhead

From: John Stracke <francis@ecal.com>
Date: Fri, 01 Dec 2000 10:04:16 -0500
Message-ID: <3A27BDF0.3A726626@ecal.com>
To: "WWW WG (E-mail)" <http-wg@cuckoo.hpl.hp.com>
Joris Dobbelsteen wrote:

> Many apache servers send data chunked. Takes a couple bytes (average of
> 4) for every block transfered. Maybe a total overhead of an additional
> 20-40 bytes per transfer (maybe less). This is just a guess...

Yes, but it's actually better than that: AFAIK, Apache uses chunked
transfer-encoding only for dynamic resources, where it can't predict the
content-length.  The alternative would be (a) buffer the output before
sending it down, or (b) defeat persistent connections.  Either (a) or (b)
would increase; (b) would actually cost extra bandwidth, and (a) would
cause bandwidth consumption to come in spikes.  So, most likely, the cost
of chunking is lower than the cost of not chunking; it's certainly lower
than the nominal overhead of the encoding.

(Sorry to those to whom this is obvious--probably including Joris--but I
didn't want to leave anybody thinking they could save bandwidth by turning
off chunking.  :-)

--
/=================================================================\
|John Stracke    | http://www.ecal.com |My opinions are my own.   |
|Chief Scientist |================================================|
|eCal Corp.      |In the country of the blind, the one-eyed man is|
|francis@ecal.com|in therapy.                                     |
\=================================================================/
Received on Friday, 1 December 2000 15:01:20 EST

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