[Pympi-users] Re: Never get to the python prompt >>>

[Mike S. <st...@gm...>]

Hi Julian,

Sorry for the late response.

> I"m currently having a problem starting up pyMPI on a simple 2 node test
> setup
> 
> 1. mpirun works correctly across 2+ plus nodes
> 2. pyMPI runs correctly if started up in single cpu mode, with -np set to 1.
> This works on both nodes.
> 3. pyMPI never gets to the >>> prompt, if I run it with -np set to 2.
> 4. I added printf statements to the pyMPI initialisation and it appears that
> both nodes complete the MPI portion (because I get duplicate printfs). The
> first (local) node then enters Py_Main and displays the credits,  but the
> second node enters Py_Main and never displays anything (assuming it should).
> 5. Result is that the process waits indefinitely for something to occur and
> never displays the >>> prompt.
> 6. I am able to ssh to th> e second node and run pyMPI with -np set to 1.

I was having identitcal problems.  After contacting Pat he pointed out
to me a configure option worth trying.  Apparently the problem is
related to I/O buffers not being properly flushed for some reason.  We
can enforce/improve this behavior by adding some options to our
configure.

However, I would first recommend that you go ahead and check out the
latest version of pyMPI from CVS.  If you're unfamiliar with how to do
that check out this page:

http://sourceforge.net/cvs/?group_id=5335

Specifically you want to execute the following:
$ cvs -d:pserver:ano...@cv...:/cvsroot/pympi login 
$ cvs -d:pserver:ano...@cv...:/cvsroot/pympi checkout pyMPI

Assuming you execute these commands from /home/cook/ it will create a
directory /home/cook/pyMPI with the most recent sources.

Now that you've got fresh sources you need to boostrap the CVS
distribution by doing( from the pyMPI directory)

$ ./boot

And then configure however you would normally but add either
"--with-isatty" or "--with-isatty --with-prompt-nl"

For instance:

$ CC=mpicc ./configure --prefix=/usr --with-isatty --with-prompt-nl
$ make 
$ ./pyMPI

There is a minor formatting glitch with this version which should be
resolved before a stable tarball is released in which the
prompt begins on the line below the >>> , like 
>>>
[]<-- cursor

Hopefully these changes will be rolled into the latest version 2.0b4
in the next few days.  I would suggest going with CVS rather then
waiting however.

Please let us know if you still have problems with the newer version
with the --with-isatty flag on.    Heck, let us know if it works for
you now as well.

Goodluck, keep us posted,

~Mike