[Click] peak packet forwarding rate measurement

[Lan Xue]

The difficulty when involving more machines than the router machine itself
is that: you need to make sure the sender is sending data from its cache.
This is pretty easy to do, you can read in some large file(s) with total
sizes smaller than the cache. Repeat this several times.

On the other side, how can you tell when the receiver would think he
receives the data? Big difference in time exists between writing to disk
vs not.

Thanks,

Lan

On Thu, 29 Jul 2004, Eddie Kohler wrote:

> > So, how would we create, for example, an input rate vs. forwarding rate
> > graph, as in the original click paper?  Would we compare the sum of the
> > "count"  handlers of the senders' InfiniteSource elements against the
> > "count" handler of a Counter element placed right before the packets
> > are
> > forwarded by the router to the receivers (the last ToDevice in the
> > configuration on the router)?
>
> That is not quite good enough, because the incoming NIC might drop some
> packets, and the outgoing NIC might drop some packets; and maintaining
> those counters will have a small, but nonzero, cost.
>
> The best way to do this is to use three [sets of] machines, and measure
> the number of packets the senders thought they sent vs. the number of
> packets the receivers actually received.  That's what we did in the
> original click paper; the scripts are available if you're interested.
>
> But you can get pretty close to that with NIC statistics counters.
>
> Eddie
>
>
>
> >
> > --Erik
> >
> > On Thu, 29 Jul 2004, Eddie Kohler wrote:
> >
> >> If you are running a kernel configuration, the handlers are available
> >> in the /click filesystem.
> >>
> >> If you are running a user level configuration, you can include a
> >> ControlSocket element and telnet to the router to see handler values
> >> (man ControlSocket).
> >>
> >> Either way, you can include a PokeHandlers element to print handler
> >> values periodically (man PokeHandlers).
> >>
> >> Eddie
> >>
> >> On Jul 29, 2004, at 1:12 PM, Lan Xue wrote:
> >>
> >>> Eddie,
> >>>
> >>> Thanks for the suggestions. Is there a way to print out the handlers
> >>> in a
> >>> real time fashion, while the router is still running? The -h option
> >>> only
> >>> allows printing out when the router is interrupted.
> >>>
> >>> Lan
> >>>
> >>> On Thu, 29 Jul 2004, Eddie Kohler wrote:
> >>>
> >>>> Lan Xue wrote:
> >>>>> Hi,
> >>>>>
> >>>>> I would like to measure the peak packet forwarding rate of click
> >>>>> router
> >>>>> given a certain setup. Does the router software itself provide any
> >>>>> functionality of doing that?
> >>>>
> >>>> The real way to measure peak forwarding rate is with multiple
> >>>> machines, one or
> >>>> more senders, a router, and one or more receivers -- then you know
> >>>> you are
> >>>> measuring exactly what you wanted.  Within Click you can use
> >>>> InfiniteSource/RatedSource packet generators, and Counter elements,
> >>>> or the
> >>>> various elements' count and drops handlers (ToDevice and FromDevice
> >>>> and
> >>>> PollDevice have them, for example), to get a genearl idea.
> >>>>
> >>>> Eddie
> >>>>
> >>
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> >> click at amsterdam.lcs.mit.edu
> >> https://amsterdam.lcs.mit.edu/mailman/listinfo/click
> >>
>
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