Re: [squid-users] Happy eyeballs

On Wed, 27 Mar 2013, Amos Jeffries wrote:
> I wrote:
> > In terms of actual page viewing its worse than that. It's as you
> > say to get the base page but then you have to repeat the wait
> > for any elements the page references (css, images etc) before
> > the browser renders the page (depending on how much parallelism
> > the browser implements in grabbing the elements).
>
> That should not be an issue unless the site has really gone out of
> its way to be unfriendly. Squid maintains an internal DNS cache
> and remembers which IPs are failing so it can try the working ones
> faster on future requests. It should also be using persistent TCP
> connections to fetch all the objects within the page (unless you
> disabled those performance features).

Well in the only test case I have at the moment that doesn't seem to
be the case and I don't believe I've disabled any of this.

Chrome's developer tools network tab shows me that if I access
http://130.123.96.119/contact-us it takes approx 3 seconds to retrieve
all 124 elements and render the page but if I try
http://karen.net.nz/contact-us then the initial page takes 10 seconds
(10 seconds waiting, 12ms receiving, fair enough) but then all the
other elements that are coming from karen.net.nz take a multiple of 10
seconds blocked (does 6 requests in parallel others block till done),
followed by 10 seconds waiting, followed by milliseconds receiving for
a total of 80 seconds to render the page.

> >> NP: connect_timeout default is still the old 60 seconds, you
> >> can
> >>
> >> safely drop it to a few seconds if you need to in 3.3.
> >
> > I've dropped it to 10 seconds as that shouldn't interfere with
> > any real site and lets sites like karen eventually render. I
> > might reduce it even more once I decide what a legitimate max
> > connect time is in todays internet.
>
> Rule-of-thumb is to use twice the ping time from somewhere on the
> far side of the world or something like that.

Well I'm hard pressed to find anywhere that has longer than 300ms
round trip these days but I dont think I want to set the
connect_timeout that low.

cheers
mark
Received on Wed Mar 27 2013 - 21:08:20 MDT