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Re: SPDY Review

From: Julian Reschke <julian.reschke@gmx.de>
Date: Thu, 07 Jun 2012 18:33:42 +0200
Message-ID: <4FD0D7E6.50403@gmx.de>
To: Martin Nilsson <nilsson@opera.com>
CC: ietf-http-wg@w3.org
On 2012-06-07 16:18, Martin Nilsson wrote:
> ...
> 2.1. Pipelining & response order
>
>    Pipelining is very important to avoid the overhead of setting up new
>    TCP connections. Limiting the number of connections is also
>    beneficial for congestion control. HTTP pipelining is defined in
>    HTTP 1.1 and Opera has spent considerable effort to make it work as
>    widely as possible. Unfortunately quite a lot of equipment doesn't
>    implement HTTP 1.1 correctly, so lots of heuristics has to be
>    applied in real world scenarios.
>
>    Given the non-uniform response times of different requests from the
>    same server, due to different amount of backend work required to
>    generate a response, pipelining is prone to stalling when a slow
>    request blocks a faster request. Out-of-order response is a good
>    solution to the problem. It can easily be added to HTTP by adding a
>    request ID header in each request and expecting corresponding
>    response IDs in the responses.
> ...

Note: that doesn't work with caching.

But see the Assoc-Req header field described in 
<http://tools.ietf.org/html/draft-nottingham-http-pipeline-00#section-5> 
-- I think it's experimentally implemented in Firefox (which means it 
needs a spec :-)

Best regards, Julian
Received on Thursday, 7 June 2012 16:34:36 GMT

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