[Bloat] when does the CoDel part of fq_codel help in the real world?

[Toke Høiland-Jørgensen]

Michael Welzl <michawe at ifi.uio.no> writes:

> However, I would like to point out that thesis defense conversations
> are meant to be provocative, by design - when I said that CoDel
> doesn’t usually help and long queues would be the right thing for all
> applications, I certainly didn’t REALLY REALLY mean that.

Just as I don't REALLY REALLY mean that bigger buffers are always better
as you so sneakily tricked me into blurting out ;)

> The idea was just to be thought provoking - and indeed I found this
> interesting: e.g., if you think about a short HTTP/1 connection, a
> large buffer just gives it a greater chance to get all packets across,
> and the perceived latency from the reduced round-trips after not
> dropping anything may in fact be less than with a smaller (or
> CoDel’ed) buffer.

Yeah, as a thought experiment I think it kinda works for the use case
you said: Just dump the entire piece of content into the network, and
let it be queued until the receiver catches up. It almost becomes a
CDN-in-the-network kind of thing (just needs multicast to serve multiple
receivers at once... ;)). Only trouble is that you need infinite queue
space to realise it...

> BTW, Anna Brunstrom was also very quick to also give me the HTTP/2.0
> example in the break after the defense.

Yup, was thinking of HTTP/2 when I said "control data on the same
connection as the payload". Can see from Pete's transcript that it
didn't come across terribly clearly, though :P 

> I’ll use the opportunity to tell folks that I was also pretty
> impressed with Toke’s thesis as well as his performance at the
> defense.

Thanks! It's been fun (both the writing and the defending) :)

> With that, I wish all the best to all you bloaters out there - thanks
> for reducing our queues!

Yes, a huge thank you all from me as well; working with the community
here has been among my favourite aspects of my thesis work!

-Toke