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From: Ralph H Castain (rhc_at_[hidden])
Date: 2007-07-11 15:26:22


I'm unaware of any issues that would cause it to fail just because it is
being run via that interface.

The error message is telling us that the procs got launched, but then
orterun went away unexpectedly. Are you seeing your procs complete? We do
sometimes see that message due to a race condition between the daemons
spawned to support the application procs and orterun itself (see other
recent notes in this forum).

If your procs are not completing, then it would mean that either the
connecting fabric is failing for some reason, or orterun is terminating
early. If you could add --debug-daemons -mca odls_base_verbose 1 to the
os.system command, the output from that might help us understand why it is
failing.

Ralph

On 7/11/07 10:49 AM, "Lev Gelb" <gelb_at_[hidden]> wrote:

>
> Hi -
>
> I'm trying to port an application to use OpenMPI, and running
> into a problem. The program (written in Python, parallelized
> using either of "pypar" or "pyMPI") itself invokes "mpirun"
> in order to manage external, parallel processes, via something like:
>
> orterun -np 2 python myapp.py
>
> where myapp.py contains:
>
> os.system('orterun -np 2 nwchem.x nwchem.inp > nwchem.out')
>
> I have this working under both LAM-MPI and MPICH on a variety
> of different machines. However, with OpenMPI, all I get is an
> immediate return from the system call and the error:
>
> "OOB: Connection to HNP lost"
>
> I have verified that the command passed to os.system is correct,
> and even that it runs correctly if "myapp.py" doesn't invoke any
> MPI calls of its own.
>
> I'm testing openMPI on a single box, so there's no machinefile-stuff currently
> active. The system is running Fedora Core 6 x86-64, I'm using the latest
> openmpi-1.2.3-1.src.rpm rebuilt on the machine in question,
> I can provide additional configuration details if necessary.
>
> Thanks, in advance, for any help or advice,
>
> Lev
>
>
> ------------------------------------------------------------------
> Lev Gelb Associate Professor Department of Chemistry, Washington University in
> St. Louis, St. Louis, MO 63130 USA
>
> email: gelb_at_[hidden]
> phone: (314)935-5026 fax: (314)935-4481
>
> http://www.chemistry.wustl.edu/~gelb
> ------------------------------------------------------------------
>
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