network performance tool

[Robert G. Brown]

On Fri, 9 Jun 2000 Jose_Maria_Gonzalez at dell.com wrote:

> Hi there,
> 
> My sincere apologise for this silly question, but does anybody know any
> either tool,program,script, or native tool in RedHat to measure the real
> network traffic on my network. I have set up a COW (8 nodes) and I am using
> MPICH 1.1.2 to run a parallel program. When I run above program the network
> traffic is very high so I just wonder if it could be a bottleneck.
> 
> I have used netperf and the latest version of SCMS which displays some
> network device information too, but it does not really help me much.

I'm not sure whether you are asking for tools like netperf or netpipe
for measuring your network's capacity or tools for monitoring the real
network traffic while you're program is running.  Netperf (or netpipe)
is about as good as it gets for measuring raw performance -- set up a
socket connection and measure what you can jam through it is basically
what either one do (with various flags controlling this and that).

I believe that both MPICH and PVM come with some examples and tools for
measuring effective network performance, but I'm not certain if those
tools (at least as described in the postscript guide) made it into the
Red Hat powertools mpich RPM.  One could presumably retrieve the sources
(which is all that you need) from a full MPICH tarball easily enough.
PVM's examples do include timing programs with the RH installation (on
the main Red Hat CD these days).

If you're looking for tools to measure the packet flow during dynamical
operation, there are BOTH tracing tools (upshot/nupshot for MPICH and
more, xpvm for PVM), some commercial tools (check the MPI/PVM websites)
and a variety of tools for monitoring raw network loads on independent
computers (e.g. procmeters of various sorts).  There are remarkably few
and poor load meters that come with RH, for whatever reason, even
including the powertools cd.  You can always try shopping on rufus 

  http://rufus.w3.org/linux/RPM/

which is what I do when I want a program for some task.  This server has
100+ GB of RPM's in a massive, cross-referenced database.  You should
likely shop the beowulf underground site as well, as they may have other
tools that have been registered that are more beowulf specific.

Finally, there is procstatd, which comes with a simple perl-tk tool and
has a template web interface in either of its source packages (it's hard
to package the web interface because webserver setups vary so widely).
Eventually I hope to add a few other interfaces (or hope that somebody
else does for me, being lazy).  procstatd has a simple interface you can
use to build your own GUI or tty tool(s) from any scripting or
programming language.  As it is currently set up, it lets you monitor up
to four ethernet interfaces (virtually every aspect of the interface as
recorded in /proc) on a whole network of hosts simultaneously.  The
provided perlTk tool (watchman) is adequate for monitoring 8-32 hosts at
once (depending on the resolution of your display) and of course you can
have multiple instances of watchman running to do more.  If I ever have
time I'll build a scrolling display, probably abandoning perlTk for Gtk
and C.  You can find the current rpm, a source rpm, and a ready-to-make
tarball, on

  http://www.phy.duke.edu/brahma

(look for the procstatd links, which point to symlinks to the current
release).  You will need to get and install a perlTk rpm on top of your
existing perl -- one that should work is provided on the brahma page but
isn't guaranteed to be particularly current.

  Hope this helps.  If it doesn't, be a bit more specific about what you
are looking for.

   rgb

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu