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Subject: Re: [OMPI users] Problem with getting started [solved]
From: Manuel Freiberger (manuel.freiberger_at_[hidden])
Date: 2008-06-13 02:12:32


Hello,

Well, actually I'm quite sure that it was not the firewall because I had to
turn it off as otherwise no connection could be established. So my
  iptables --list
returns

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

on both machines. After reinstalling OMPI, I did not make any changes to the
firewall but now it works without problems. Probably installing the library
with exactly the same configuration (same --prefix and so on) did the trick.

But nonetheless, thank you very much for your hint! :-)

Best regards,
Manuel

On Thursday 12 June 2008 18:23, Rainer Keller wrote:
> Hi,
> are You sure it was not a Firewall issue on the Suse 10.2?
> If there are any connections from the Gentoo machine trying to access the
> orted on the Suse, check in /var/log/firewall.
>
> For the time being, try stopping the firewall by (as root) with
> /etc/init.d/SuSEfirewall2_setup stop
> and test whether it works ,-]
>
> With best regards,
> Rainer
>
> On Donnerstag, 12. Juni 2008, Manuel Freiberger wrote:
> > Hi!
> >
> > Ok, I found the problem. I reinstallen OMPI on both PCs but this time
> > only locally in the users home directory. Now, the sample code works
> > perfectly. I'm not sure where the error really was located. It could be
> > that it was a problem with the Gentoo installation because OMPI is still
> > marked unstable in portage (~x86 keyword).
> >
> > Best regards,
> > Manuel
> >
> > On Wednesday 11 June 2008 18:52, Manuel Freiberger wrote:
> > > Hello everybody!
> > >
> > > First of all I wanted to point out that I'm beginner regarding openMPI
> > > and all I try to achieve is to get a simple program working on two PCs.
> > > So far I've installed openMPI 1.2.6 on two PCs (one running OpenSUSE
> > > 10.2, the other one Gentoo).
> > > I set up two identical users on both systems and made sure that I can
> > > make an SSH connection between them using private/public key
> > > authentication.
> > >
> > > Next I ran the command
> > > mpirun -np 2 --hostfile myhosts uptime
> > > which gave the result
> > > 6:41pm up 1 day 5:16, 4 users, load average: 0.00, 0.07, 0.17
> > > 18:43:45 up 7:36, 6 users, load average: 0.00, 0.02, 0.05
> > > so I concluded that MPI should work in principle.
> > >
> > > Next I tried the following code which I copied from Boost.MPI:
> > > ---- snip
> > > #include <mpi.h>
> > > #include <iostream>
> > >
> > > int main(int argc, char* argv[])
> > > {
> > > MPI_Init(&argc, &argv);
> > > int rank;
> > > MPI_Comm_rank(MPI_COMM_WORLD, &rank);
> > > if (rank == 0)
> > > {
> > > std::cout << "Rank 0 is going to send" << std::endl;
> > > int value = 17;
> > > int result = MPI_Send(&value, 1, MPI_INT, 1, 0, MPI_COMM_WORLD);
> > > if (result == MPI_SUCCESS)
> > > std::cout << "Rank 0 OK!" << std::endl;
> > > }
> > > else if (rank == 1)
> > > {
> > > std::cout << "Rank 1 is waiting for answer" << std::endl;
> > > int value;
> > > MPI_Status status;
> > > int result = MPI_Recv(&value, 1, MPI_INT, 0, 0, MPI_COMM_WORLD,
> > > &status);
> > > if (result == MPI_SUCCESS && value == 17)
> > > std::cout << "Rank 1 OK!" << std::endl;
> > > }
> > > MPI_Finalize();
> > > return 0;
> > > }
> > > ---- snap
> > >
> > > Starting a parallel job using
> > > mpirun -np 2 --hostfile myhosts mpi-test
> > > I get the answer
> > > Rank 0 is going to send
> > > Rank 1 is waiting for answer
> > > Rank 0 OK!
> > > and than the program locks. So the strange thing is that obviously the
> > > recv()-command is blocking, which is what I do not understand.
> > >
> > > Could anybody provide some hints, where I should start looking for the
> > > mistake? Any help is welcome!
> > >
> > > Best regards,
> > > Manuel

-- 
Manuel Freiberger
Institute of Medical Engineering
Graz University of Technology
manuel.freiberger_at_[hidden]