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From: Robert Latham (robl_at_[hidden])
Date: 2006-03-14 13:59:52

On Tue, Mar 14, 2006 at 12:00:57PM -0600, Edgar Gabriel wrote:
> you are touching here a difficult area in Open MPI:

I don't doubt it. I haven't found an MPI implementation yet that does
this without any quirks or oddities :>

> - name publishing across independent jobs does unfortunatly not work
> right now (It does work, if all processes have been started by the
> same mpirun or if the have been spawned by a father process using
> MPI_Comm_spawn). Your approach with passing the port as a command
> line option should work however.
> - you have to start however the orted daemon *before* starting both
> jobs using the flags ' orted --seed --persistent --scope public'
> These flags are however currently just lightly tested, since a
> brand new runtime environment with much better support for these
> operations is currently under development.

Ok, got it. If there is some sort of setup before hand (in this
case, lanuching orted), then these independent mpi processes will
have a lot easier time talking to each other. Makes sense.

> - regarding the 'pack data mismatch': do both machines which you are
> using have the same data representation? The reason I ask is
> because this looks like a data type mismatch error, and Open MPI
> currently does have some restriction regarding different data
> formats and endianness...

I'm just running this on the same machine.

Thanks for the quick response.

Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Labs, IL USA                B29D F333 664A 4280 315B