launchpad-dev team mailing list archive

[Edwin Grubbs <edwin.grubbs@xxxxxxxxxxxxx>]

On Wed, Nov 18, 2009 at 9:19 PM, Robert Collins
<robertc@xxxxxxxxxxxxxxxxx> wrote:
> On Wed, 2009-11-18 at 16:12 -0600, Edwin Grubbs wrote:
>>
>> Leonard already mentioned HTTP Pipelining, but I didn't see any
>> explanation why we wouldn't want to use that instead of our own custom
>> header processing.
>
> Don't use or depend on HTTP pipelining.
>
> Its a security and correctness nightmare.
>
> -Rob

Since you didn't define which security and correctness nightmares that
HTTP pipelining introduces, I tried to google for an answer. All I
could find were criticisms that pipeling would make it hard to detect
DOS attacks and that its performance improvements are limited because
the spec requires that the responses are sent in the same order as the
requests, which can prevent quick results from being sent before slow
results are finished. Rolling our own solution would allow us to
circumvent pipelining's ordering requirement, but I am wondering if we
will run into all of its other drawbacks such as networking equipment
servers handling more and more long running connections.

I stumbled upon an interesting proof of concept of this idea. The
DUI.Stream javascript library actually parses each chunk of data as it
comes in by polling the request.responseText attribute every 15ms
after the request enters the LOADING state. It expects the response to
be in multipart/mixed mime format.

http://about.digg.com/blog/duistream-and-mxhr

-Edwin