Scaling BFD support

[Douglas Fischer]

Hello Arnold
Thank you for the information!

Are there any public docs or references of that workshop?


Sincerely, what caught my attention was the "Auth: none" part.
On a room with more than thousand persons, confirm if the voice you
rear is really from the person you think it is makes sense to me.


But the good part is that the interval is not crazily small as some wanted.
This reduces the number of pps the deamon has to deal with.

Using the biggest IXP in number os participants as a reference.
Assuming all participants active BFD, there are 2500 BFD session per server
per protocol(v4+v6)
Assuming that the minimum interval(500ms) is always used(worst case
scenario).
2750*2*=11.000pps
I don't know if that is feasible for an engine without any improvements of
performance.


Em qui., 23 de jun. de 2022 às 08:52, Arnold Nipper <arnold at nipper.de>
escreveu:

> Douglas
>
> there was a workshop on "BFD at IXes" at the recent Euro-IX Forum in
> Tampere.
>
> These are the parameters the participants agreed upon
>
>   * Interval: 500ms - 1500ms
>   * Multiplier: 3 or 5
>   * Passive: on
>   * Idle_tx: 3x Interval
>   * Auth: none
>
>
> Greetings
> Arnold
>
> On 18.06.2022 13:47, Douglas Fischer wrote:
> > Hello all!
> >
> > Just passing here to see if any moves on this BFD Scaling occurred.
> >
> > This week some friends that are involved in the operation of a really
> > big IXP told me that they were having problems with some "funny"
> > participants of its IXP that adjusted their BGP Timer to numbers like
> 5/15.
> > On an environment with thousands of peers, I'm sure you can imagine the
> > CPU impact of that.
> >
> > Now you are probably asking:
> > What that has to do with Scale the BFD capacities on BIRD?
> >
> > Well...
> > Those 'j'enius are probably adjusting the timers to have some kind of
> > control of some communication issue occurs between his router and the RS.
> > They just "forget" that on that level of reduction, it compromises the
> > processing capacity of the RS.
> >
> > If BFD engine could support session for every participant at IXP, or at
> > least for those that wants that kind of resource.
> > Then would be reasonable to lock the timers of BGP Session in 60/180.
> >
> >
> > Em sex., 1 de abr. de 2022 às 13:41, Ondrej Zajicek
> > <santiago at crfreenet.org <mailto:santiago at crfreenet.org>> escreveu:
> >
> >     On Fri, Apr 01, 2022 at 08:44:50AM -0300, Douglas Fischer wrote:
> >      > The question raised by colleague Irene reminded me of a topic
> >     that may or
> >      > may not be the focus of BIRD's development.
> >      >
> >      > I imagine that the biggest supporters of
> SMP/Multi-Core/Thread-Safe
> >      > evolution on BIRD are Operators of Route-Servers of large IXPs,
> and
> >      > operators of large-scale Route-Reflectors.
> >      >
> >      > Although BFD has its greatest use in the transport network and
> >     Underlay, it
> >      > is increasingly common to see the use of BFD in BGP Internet.
> >      >
> >      > I'm personally overly excited about what BIRD version 3 is
> >     demonstrating in
> >      > terms of vertical scalability.
> >      >
> >      > But I keep imagining that, even having scalability in the BGP
> >     engine, it is
> >      > almost prohibitive to use BFD in a scenario with a thousand BGP
> >     Peers.
> >      >
> >      > Is there any view from the IBRD development team for this matter?
> >      > Or even... Is there any open project focused on BFD that can
> >     address this?
> >
> >     Hmm, that is a good point. It would make sense to have multiple BFD
> >     threads, but i think that it is more a question of improving I/O loop
> >     performance in BIRD, as thousand peers with 100ms period is about 10
> >     kpps
> >     UDP rate, which should be manageable even from a single thread. We
> >     should
> >     make some effort to do some benchmarking for BFD.
> >
> >     --
> >     Elen sila lumenn' omentielvo
> >
> >     Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org
> >     <mailto:santiago at crfreenet.org>)
> >     OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3,
> >     wwwkeys.pgp.net <http://wwwkeys.pgp.net>)
> >     "To err is human -- to blame it on a computer is even more so."
> >
> >
> >
> > --
> > Douglas Fernando Fischer
> > Engº de Controle e Automação
>
>
> --
> Keep calm, keep distance, keep connected!
>
> Arnold Nipper
> email: arnold at nipper.de
> mobile: +49 172 2650958
>


-- 
Douglas Fernando Fischer
Engº de Controle e Automação
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