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Interesting critique of SPDY

From: Noah Mendelsohn <nrm@arcanedomain.com>
Date: Fri, 13 Jul 2012 10:56:06 -0400
Message-ID: <50003706.9000508@arcanedomain.com>
To: "www-tag@w3.org" <www-tag@w3.org>
CC: Mark Nottingham <mnot@mnot.net>
An interesting critique of SPDY has been posted, and may be of interest to 
TAG members who are following the protocol space. I think the points about 
routers and performance are very interesting, and not something we've 
discussed. Quoting:

In the time frame where HTTP/2.0 will become standardized, HTTP routers 
will routinely deal with 40Gbit/s traffic and people will start to arcitect 
for 1Tbit/s traffic.

So, that's about 4GBytes/sec. If we assume that a modern CPU core processes 
maybe, well by coincidence, on the order of a few billion instructions/sec, 
we're on the order of 1 CPU instruction per byte. Now, there will be 
multiple cores, specialized hardware might scan for packet headers, etc., 
but it's not hard to convince yourself that some serious optimization and 
performance tuning is needed just to keep up.

Stated differently: building protocols that make it unnecessarily hard to 
recognize and filter headers, or that require decompression to find them, 
could really limit the ability of routers and firewalls to do the work they 
need to do, including protecting from Denial of Service attacks. The 
implication is that SPDY is a step backward, not forward, in these respects.

Noah

[1] https://www.varnish-cache.org/docs/trunk/phk/http20.html
Received on Friday, 13 July 2012 14:56:37 GMT

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