Re: [Cake] Pre-print of Cake paper available

["Toke Høiland-Jørgensen" <toke@toke.dk>]

Pete Heist <pete@eventide.io> writes:

>> On Apr 25, 2018, at 10:28 PM, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>> 
>> Hmm, actually it looks like just compiling against the conntrack code
>> adds a module dependency on conntrack. And as far as I can tell, the
>> code doesn't initiate any new conntrack state if it doesn't already
>> exist. So I think it's safe to turn on NAT mode by default. Will add
>> that :)
>
> nat vs nonat CPU load for flent’s rrul_be / "cpu_stats_localhost::load" on APU2:
>
> <limit> <nonat avg cpu load> <nat avg cpu load>
> 10mbit  0.07  0.07
> 20mbit  0.09  0.09
> 30mbit  0.10  0.10
> 40mbit  0.11  0.11
> 50mbit  0.13  0.13
> 100mbit  0.19  0.20
> 150mbit  0.27  0.28
> 200mbit  0.33  0.35
> 250mbit  0.39  0.41
> 300mbit  0.44  0.45
> 350mbit  0.47  0.47
> 400mbit  0.50  0.49
> 450mbit  0.50  0.51
> 500mbit  0.53  0.52
> none  0.37  0.43 (1864 mbit total up/down)
>
> It looks like the largest impact is when there’s no rate limiting,
> probably when higher packet rates are reached and the relative
> proportion of CPU taken is greater. I suppose the backwards results
> (where nonat takes more CPU than nat) at 400mbit and 500mbit are just
> outliers. This isn’t a perfect way to measure.
>
> I’ll leave it to you what to do with this information. Rough
> estimation: nat may be +2% CPU with rate limiting, and +15% without…

Huh, that is maybe a bit much for a default; I guess it's better to just
set the NAT flag as needed from sqm-scripts, then...

-Toke