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Subject: Re: [OMPI users] Cluster : received unexpected process identifier
From: Rohan Deshpande (rohand87_at_[hidden])
Date: 2012-04-04 19:55:35


Hi,

I am not quite sure what does that mean. Can you please explain more.

Thanks

On Wed, Apr 4, 2012 at 10:47 PM, Jeffrey Squyres <jsquyres_at_[hidden]> wrote:

> Do you have multiple IP interfaces on a single machine on the same IP
> subnet, perchance?
>
> If so, don't do that. :-) Put each of your IP addresses in a different
> IP subnet.
>
>
> On Apr 3, 2012, at 10:30 PM, Rohan Deshpande wrote:
>
> > Hi,
> >
> > I am running a MPI program using cluster and tcp communication.
> >
> > To run I am using: mpirun --prefix /usr/local/ --mca btl tcp,self
> --hostfile slaves -np 6 scatter
> >
> >
> > I am getting following output:
> >
> > Process 0 on host host1 has elements 0 1 2 3
> > Process 1 on host host1 has elements 4 5 6 7
> > Process 2 on host host1 has elements 8 9 10 11
> > Process 3 on host host1 has elements 12 13 14 15
> >
> [slave1][[24708,1],5][btl_tcp_endpoint.c:486:mca_btl_tcp_endpoint_recv_connect_ack]
> received unexpected process identifier [[24708,1],4]
> >
> > When trying to communicate with slave1 i get received unexpected process
> identifier error.
> >
> > My PATH and LD_LIBRARY_PATH are correctly set in .bashrc file.
> >
> >
> >
> > Source code -
> >
> >
> > #include <stdlib.h>
> > #include <stdio.h>
> > #include "mpi.h"
> > #define MAXPROC 8 /* Max number of procsses */
> > #define LENGTH 24 /* length of buffer */
> >
> > int main(int argc, char* argv[]) {
> > int i, j, np, me;
> > const int nametag = 40; /* Tag value for sending name */
> > const int datatag = 45; /* Tag value for sending data */
> > const int root = 0; /* Root process in scatter */
> > MPI_Status status; /* Status object for receive */
> >
> > char myname[MPI_MAX_PROCESSOR_NAME]; /* Local host name string */
> > char hostname[MAXPROC][MPI_MAX_PROCESSOR_NAME]; /* Received host
> names */
> > int namelen;
> >
> > int x[LENGTH]; /* Send buffer */
> > int y[LENGTH]; /* Receive buffer */
> >
> > MPI_Init(&argc, &argv); /* Initialize MPI */
> > MPI_Comm_size(MPI_COMM_WORLD, &np); /* Get nr of processes */
> > MPI_Comm_rank(MPI_COMM_WORLD, &me); /* Get own identifier */
> >
> > MPI_Get_processor_name(myname, &namelen); /* Get host name */
> > myname[namelen++] = (char)0; /* Terminating null byte */
> >
> > /* Check that we have an even number of processes and at most MAXPROC
> */
> > if (np>MAXPROC || np%2 != 0) {
> > if (me == 0) {
> > printf("You have to use an even number of processes (at most
> %d)\n", MAXPROC);
> > }
> > MPI_Finalize();
> > exit(0);
> > }
> >
> > if (me == 0) { /* Process 0 does this */
> >
> > /* Initialize the array x with values 0 .. LENGTH-1 */
> > for (i=0; i<LENGTH; i++) {
> > x[i] = i;
> > }
> >
> > printf("Process %d on host %s is distributing array x to all %d
> processes\n\n",
> > me, myname, np);
> >
> > /* Scatter the array x to all proceses, place it in y */
> > MPI_Scatter(x, LENGTH/np, MPI_INT, y, LENGTH/np, MPI_INT, root,
> > MPI_COMM_WORLD);
> >
> > /* Print out own portion of the scattered array */
> > printf("Process %d on host %s has elements", me, myname);
> > for (i=0; i<LENGTH/np; i++) {
> > printf(" %d", y[i]);
> > }
> > printf("\n");
> >
> > /* Receive messages with hostname and the scattered data */
> > /* from all other processes */
> > for (i=1; i<np; i++) {
> > MPI_Recv (hostname[i], namelen, MPI_CHAR, i, nametag,
> MPI_COMM_WORLD,
> > &status);
> > MPI_Recv (y, LENGTH/np, MPI_INT, i, datatag, MPI_COMM_WORLD,
> &status);
> > printf("Process %d on host %s has elements", i, hostname[i]);
> > for (j=0; j<LENGTH/np; j++) {
> > printf(" %d", y[j]);
> > }
> > printf("\n");
> > }
> >
> > printf("Ready\n");
> >
> >
> > } else { /* all other processes do this */
> >
> > /* Receive the scattered array from process 0, place it in array y */
> > MPI_Scatter(x, LENGTH/np, MPI_INT, y, LENGTH/np, MPI_INT, root, \
> > MPI_COMM_WORLD);
> > /* Send own name back to process 0 */
> > MPI_Send (myname, namelen, MPI_CHAR, 0, nametag, MPI_COMM_WORLD);
> > /* Send the received array back to process 0 */
> > MPI_Send (y, LENGTH/np, MPI_INT, 0, datatag, MPI_COMM_WORLD);
> >
> > }
> >
> > MPI_Finalize();
> > exit(0);
> > }
> >
> > Any idea what could be wrong?
> >
> >
> > Thanks
> >
> >
> >
> >
> >
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>

-- 
Best Regards,
ROHAN DESHPANDE