1304295 - Initially open two connections for base page loads

Status: RESOLVED WONTFIX

(Core :: Networking: HTTP, defect, P3)

Description

[Dão Gottwald [:dao]]

From bug 1301988 comment 8:

(In reply to Patrick McManus [:mcmanus])
> (In reply to bugzilla)
> > (In reply to Patrick McManus [:mcmanus])
> > 
> > > we use a history algorithm to try and decide how many connections an origin
> > > typically needs rather than this hardcode. Obviously there are plusses and
> > > minuses.
> > 
> > If the history algorithm worked on connections 3 - 6 rather than 2 to 6, and
> > connection 2 was openned simulaneously with connection 1 wouldn't this small
> > change give the best of both worlds given most modern websites have
> > considerably more than a handful of constituent objects?
> 
> 
> modern websites run http/2 which only need one.. so we're chasing a
> shrinking market there.  but I don't want to make a big fuss - 2 wouldn't be
> a problem
> 
> > 
> > Otherwise IE always going to be faster as it is initially opening 2
> > connections and then parsing the html counting the objects to simultaneously
> > opening up to 6 connections. 
> > 
> > When combined with downloading the favicon after the page has loaded this
> > makes a real world difference to the user's perception of a browser’s speed.
> > For example in the attached waterfall example Firefox hasn't started to
> > render the first row of images when IE has completed the page.

Comment 1

[bugzilla]

Attachment: Waterfall graphs showing Nightly connections sitting idle

Nightly is opening the connections earlier which is good. 

However the connections are sitting idle until the header objects have been processed rather than loading synchronously. In the attached example this will shave a further 120ms of the page load bringing Nightly much closer to IE's speed. 

Nightly
https://www.webpagetest.org/result/160923_93_CFZ/1/details/#waterfall_view_step1

IE 11
https://www.webpagetest.org/result/160923_B4_D6Z/1/details/#waterfall_view_step1

Comment 2

[Dragana Damjanovic [:dragana]]

Initializing second connection it would be ok.

Comment 3

[bugzilla]

Quick update on opening 2 connections straight after the DNS has replied.

Chrome opens 3 initial connections straight after the DNS instead of 2 under some circumstances. (A further 3 instead of 4 are then opened later after the html has completed loading.)

The trigger for this approach seems to be distance to the server.

Comment 4

[Julien Cristau [:jcristau]]

Mass wontfix for bugs affecting firefox 52.

Comment 5

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 6

[Sylvestre Ledru [:Sylvestre]]

Moving to p3 because no activity for at least 1 year(s).
See https://github.com/mozilla/bug-handling/blob/master/policy/triage-bugzilla.md#how-do-you-triage for more information

Comment 7

[Sunil Mayya]

We do not plan to fix this, given the fact that this is only applicable for H1 and possible regressions that will be introduced with this bug.