Luigi Rizzo wrote:
>
> > There's one downside though. You can get statistics from the bridge node on
> > packets and octects passed through the different parts of the bridge
> > setyup, but it's not IP based. Also using that bridging code there's no
> > bandwidth throttling or IPFW rule matching yet.
> >
> > Vitaly Belekhov wrote BW throttling and ipfw netgraph nodes for 3.X, and I
> > will be porting those to 5.X-CURRENT over the next few weeks.
The new ethernet node netgrpah interface (with 'upper' and 'lower')
may influence this.
also the ipfw he used is very old now.
> >
> > Using those you could get statistics really quickly by using libnetgraph
> > and querying the nodes yourself with some C code instead of shell/perl
> > scripting.
>
> the real problem with any approach is that if you have very many
> flows, you have to fetch all the info every time you want to update
> your statistics. The ipfw implementation which is in the kernel
> now really does not help you there, because the stats are spread
> over lists and hash tables, and on top of this the data structure
> evolves dynamically as pkts come in, so you need to hold a lock
> while navigating on it.
>
> This is why you do not want to download the stats 10-20 times per
> second, at least with this architecture.
>
> I do not have a good solution in mind other than maybe
> change the data structures so that the flow descriptors
> (at least the part with the flow identifier and the stats)
> are in a contiguous chunk of memory whose only variable
> part is the size. This way you can either mmap the block,
> or copyout() it without having to get a lock.
>
> cheers
> luigi
> ----------------------------------+-----------------------------------------
> Luigi RIZZO, [EMAIL PROTECTED] . ACIRI/ICSI (on leave from Univ. di Pisa)
> http://www.iet.unipi.it/~luigi/ . 1947 Center St, Berkeley CA 94704
> Phone: (510) 666 2927
> ----------------------------------+-----------------------------------------
>
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