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<p>$ mpiexec -n 2 -f hostfile ./mpi/mpich-3.3.1/examples/cpi<br />Process 1 of 2 is on csews2<br />Process 0 of 2 is on csews1<br />Fatal error in PMPI_Reduce: Unknown error class, error stack:<br />PMPI_Reduce(523)................: MPI_Reduce(sbuf=0x7ffeab580c10, rbuf=0x7ffeab580c18, count=1, datatype=MPI_DOUBLE, op=MPI_SUM, root=0, comm=MPI_COMM_WORLD) failed<br />PMPI_Reduce(509)................: <br />MPIR_Reduce_impl(316)...........: <br />MPIR_Reduce_intra_auto(231).....: <br />MPIR_Reduce_intra_binomial(125).: <br />MPIDI_CH3U_Recvq_FDU_or_AEP(629): Communication error with rank 1</p>
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<p>Can anyone explain this error and how to overcome it.I have installed just MPICH and not HYDRA package.</p>
<p>By the way this same command works fine with hello program the one where each node says their identity.</p>
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