Re: #282: Recommend minimum sizes for protocol elements

On 02/05/2011, at 5:12 PM, Poul-Henning Kamp wrote:

> In message <>, Willy Tarreau writes:
>>> PS: Is it just me or are large pointless HTTP-headers an indicator of
>>> mobile devices where users pay for bandwidth ?
>> It may be just you :-)
> Check the headers from a device rhyming with "Jack&Terry" :-)
> It may be that the headers are added in a land-side proxy, but
> they are somewhat obese still.
>> BTW this makes me think that there are 3 request headers which are
>> responsible for something like 80% of the upstream bandwidth :
>> - User-Agent
>> - Cookie
>> - Referer
> One of the more amusing ways to bust caches is to include "Vary:
> User-agent" in a response.
> One would think that there would be two identical browsers on the
> planet but I guess we're all individualists in that respect.
> I think that we should recommend that clients not send
> a U-A header at all, to enourage servers to DTRT with respect
> to content portablity.

Agreed, but from discussing this (at length) with browser vendors, they're unwilling to change UA and other headers much, because of potential interop problems with sites that depend upon them.

There has been some headway in recent browsers; IE9 and FF4 have somewhat shorter UA headers than before.

I'm currently cooking up a workaround for this; should have a draft soon.


Mark Nottingham

Received on Monday, 2 May 2011 07:15:36 UTC