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Re: Idempotent partial updates

From: Mark Nottingham <mnot@mnot.net>
Date: Thu, 1 Mar 2012 09:56:16 +1100
Cc: Amos Jeffries <squid3@treenet.co.nz>, ietf-http-wg@w3.org
Message-Id: <67D06259-02BB-443B-88E0-E4E3C350DE46@mnot.net>
To: Adrien de Croy <adrien@qbik.com>

On 01/03/2012, at 9:34 AM, Adrien de Croy wrote:

> Last time I sampled Cache-control response headers (over couple million hits crawling sites), I found a large majority use it to prevent caching.  Very few to enable it.  It's a shame.
> so moving from a naive HTTP/1.0 style cache to a compliant HTTP/1.1 style cache actually resulted in a huge reduction in cache utility.  Without ignoring cache-control directives as you say, it's hard to get more than a 10% effective bandwidth benefit from caching, which frankly is not worth the pain.

Not sure what you're crawling, but my experience is that effective bandwidth savings is MUCH higher, even on a conservatively configured cache.

And anecdotal evidence suggests it's getting better; see:

http://httparchive.org/trends.php (~45% of responses have caching headers)
http://httparchive.org/interesting.php  (~40% of responses with CC have a max-age > 0)

 and if you restrict to the top 1000 sites, both numbers are higher, about 60% each. Combined with heuristic freshness, what's the problem?


Mark Nottingham
Received on Wednesday, 29 February 2012 22:56:59 UTC

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