[Nfd-dev] Maximum FIB size

[Davide Pesavento]

On Wed, Jan 13, 2016 at 11:29 PM, Bruno Ricci <bruno.ricci at uniroma2.it> wrote:
> Hi guys,
>
> first of all, thank you for your answers.
>
> All we did was run a bash script that calls nfdc register. All routes are
> random string of 16 chars, and are set towards a random IP address using
> UDP. As simple as (pseudocode)
>
> for i in 1..100000
> do
>   ip=random(3.3.3.3)
>   name=random(16)
>   nfdc register ndn:/$name  udp://$ip
>   sleep 1
> done
>
> This runs fine without errors (at least with the default debug level), until
> NFD silently crashes. As Junxiao pointed out, maybe the problem relies on
> the number of faces, and not on the FIB size (I honestly haven't thought
> about that, thanks for pointing that out). I will try tomorrow morning at
> work to re run the script reducing the faces number, and to run NFD inside
> gdb.
>
> I will keep you posted, thanks again.
>
> Bruno
>

Hi Bruno,

I'm pretty sure you went well over the maximum number of open file
descriptors allowed by the system, e.g. it's normally set to 1024 on
ubuntu linux. This happens because for every prefix you register,
you're also implicitly creating a new face. And each face needs a
socket, which means an open file descriptor. So basically you're
trying to open 100k fds... (or a bit less if some of the generated IPs
are duplicates).

HTH!

Ciao,
Davide