[Bloat] SFB tuning (was Re: Applying RED93 in south africa)

[Otto Solares Cabrera <solca@guug.org>]

On Sat, May 28, 2011 at 10:07:10PM +0200, Juliusz Chroboczek wrote:
> > SFB is also in this release, but lacking good scripts for it...
> 
> SFB is supposed to be self-tuning, so it should be enough to say
> something like:
> 
>   #!/bin/sh
>   set -e
> 
>   if=${1:-eth0}
> 
>   tc -s qdisc del root dev $if 2>/dev/null || true
>   tc -s qdisc add dev $if root handle 1: tbf ...
>   tc -s qdisc add dev $if parent 1: handle 2: sfb
> 
> However, I may have made the SFB defaults a little bit too conservative
> (leading to high stability but slow convergence), so you may want to
> make it a little bit more aggressive by replacing the last line with:
> 
>   tc -s qdisc add dev $if parent 1: handle 2: sfb target 20 max 25 increment 0.005 decrement 0.0001

Hello Juliusz,

I'm using SFB on a production env, on the external interface to the
Internet (100Mbps ethernet capped to 70Mbps by the ISP):

tc qdisc add dev eth4 parent 1:3  handle 13:  sfb hash-type source limit 100 target 10 max 15 penalty_rate 60

And on the internal interfaces (1Gbps ethernet) to clients like this:

tc qdisc add dev ${DEV} parent 50:20 handle 52: sfb hash-type dest limit 100 target 10 max 15 penalty_rate 100

Everything is working stable and I would like a recommendation if it
looks fine or if something could be tuned?

Thank you!
-
 Otto