[j-nsp] Hardware configuration for cRPD as RR

[Saku Ytti]

>From a RPD, not cRPD perspective.

- 64GB is certainly fine, you might be able to do with 32GB
- Unless RRs are physically next to clients, you want to bump default
16kB TCP window to maximum 64kB window, and probably ask account team
for window scaling support (unsure if this is true for cRPD, or if
cRPD lets underlying kernel do this right, but you need to do same in
client end anyhow)
- You absolutely need sharding to put work on more than 1 core.

Sharding goes up-to 31, but very likely 31 is too much, and the
overhead of sharding will make it slower than running lower counts
like 4-8. Your core count likely shouldn't be higher than shards+1.

The sharding count and DRAM count are not specifically answerable, as
it depends on what the contents of the RIB is. Do a binary search for
both and measure convergence time, to find a good-enough number, I
think 64/32GB and 4-8 cores are likely good picks.

On Wed, 6 Dec 2023 at 22:30, Thomas Scott via juniper-nsp
<juniper-nsp at puck.nether.net> wrote:
>
> Also very curious in this regard.
>
> Best Regards,
> -Thomas Scott
>
>
> On Wed, Dec 6, 2023 at 12:58 PM Vincent Bernat via juniper-nsp <
> juniper-nsp at puck.nether.net> wrote:
>
> > Hey!
> >
> > cRPD documentation is quite terse about resource requirements:
> >
> > https://www.juniper.net/documentation/us/en/software/crpd/crpd-deployment/topics/concept/crpd-hardware-requirements.html
> >
> > When used as a route reflector with about 20 million routes, what kind
> > of hardware should we use? Documentation says about 64 GB of memory, but
> > for everything else? Notably, should we have many cores but lower boost
> > frequency, or not too many cores but higher boost frequency?
> >
> > There is a Day One book about cRPD, but they show a very outdated
> > processor (Sandy Lake, 10 years old).
> >
> > Is anyone using cRPD as RR with a similar scale and can share the
> > hardware configuration they use? Did you also optimize the underlying OS
> > in some way or just use a stock configuration?
> >
> > Thanks.
> > _______________________________________________
> > juniper-nsp mailing list juniper-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/juniper-nsp
> >
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp



-- 
  ++ytti