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From: Arved Sandstrom on 1 Apr 2010 05:24
Kevin McMurtrie wrote:
> In article <alpine.DEB.1.10.1003312344430.13579(a)urchin.earth.li>,
> Tom Anderson <twic(a)urchin.earth.li> wrote:
>
>> On Wed, 31 Mar 2010, Roedy Green wrote:
>>
>>> Everyone has seen that sending one big file works much more efficiently
>>> than many small files. The effect quite astounding, many orders of
>>> magnitude. It just occurred to me that I don't think I can account for
>>> that huge difference. Where is all the time going?
>> TCP handshake, TCP slow start (look that one up if you don't know it),
>> roundtrips for control packets at the start of the connection. Losing a
>> bit of time can have a huge impact on throughput - it's all about the
>> bandwidth-delay product, which on today's long, fat networks is huge.
>>
>>> It then occurred to me, that any sort of technique to reduce the
>>> difference could have a huge effect on the Internet as a whole.
>> Yes. It's called pipelining, and it's been in HTTP since 1999.
>>
>> Although it's not that widely used by browsers, because of worries about
>> compatibility with servers, which seems a bit of a waste.
>>
>> tom
>
> Browsers don't support pipelining because the multiplexer/demultiplexer
> is too complicated for the average software engineer.
[ SNIP ]
AHS

Simple solution - don't use average software engineers to work on this
code. There are how many significant web browsers again? Surely it's not
so tough to ensure that the 2 or 3 people per important browser, maybe a
dozen people for the planet overall, are above-average.

Average software engineers (programmers in countries where you can't
legally call a programmer an engineer, or in the US where it's usually a
misnomer) can't reliably code chunked transfer encoding either, yet
significant web browsers have that feature.

If 10% of all programmers are competent to work on problems like this
(that might be generous, it might be 3 or 5 percent) then you've still
got hundreds of thousands of people that can do it.

AHS
From: Tom Anderson on 1 Apr 2010 11:02
On Thu, 1 Apr 2010, Kevin McMurtrie wrote:

> In article <alpine.DEB.1.10.1003312344430.13579(a)urchin.earth.li>,
> Tom Anderson <twic(a)urchin.earth.li> wrote:
>
>> On Wed, 31 Mar 2010, Roedy Green wrote:
>>
>>> Everyone has seen that sending one big file works much more efficiently
>>> than many small files. The effect quite astounding, many orders of
>>> magnitude. It just occurred to me that I don't think I can account for
>>> that huge difference. Where is all the time going?
>>
>> TCP handshake, TCP slow start (look that one up if you don't know it),
>> roundtrips for control packets at the start of the connection. Losing a
>> bit of time can have a huge impact on throughput - it's all about the
>> bandwidth-delay product, which on today's long, fat networks is huge.
>>
>>> It then occurred to me, that any sort of technique to reduce the
>>> difference could have a huge effect on the Internet as a whole.
>>
>> Yes. It's called pipelining, and it's been in HTTP since 1999.
>>
>> Although it's not that widely used by browsers, because of worries about
>> compatibility with servers, which seems a bit of a waste.
>
> Browsers don't support pipelining because the multiplexer/demultiplexer
> is too complicated for the average software engineer.

Opera - uses pipelining
Firefox - supports pipelining, not turned on by default
Konqueror - supports pipelining, not turned on by default
IE - does not support pipelining
Safari - does not support pipelining

I guess Opera, Mozilla and KDE all have above-average engineers.

> Last I heard, Microsoft and Apache clients can't pipeline;

No surprise about MS. What's the Apache client? I'm not aware of a browser
made by Apache - do you mean some non-browser client? HttpClient, perhaps?

tom

--
The question of whether computers can think is just like the question
of whether submarines can swim. -- Edsger W. Dijkstra
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