That should work, then. When you set the "host" property, did you give the same name as was in your machine file?
Debug options that might help: -mca plm_base_verbose 5 -mca rmaps_base_verbose 5 You'll need to configure --enable-debug to get the output, but that should help tell us what is happening. On Aug 16, 2011, at 5:09 AM, Simone Pellegrini wrote: > On 08/16/2011 12:30 PM, Ralph Castain wrote: >> What version are you using? > > OpenMPI 1.4.3 > >> >> >> On Aug 16, 2011, at 3:19 AM, Simone Pellegrini wrote: >> >>> Dear all, >>> I am developing a system to manage MPI tasks on top of MPI. The >>> architecture is rather simple, I have a set of scheduler processes which >>> takes care to manage the resources of a node. The idea is to have 1 (or >>> more) of those scheduler allocated on each node of a cluster and then >>> create new MPI processes (on demand) as computation is needed. Allocation >>> of processes is done using MPI_Spawn. >>> >>> The system now works fine on a single node by allocating the main scheduler >>> using the following mpi command: >>> mpirun --np 1 ./scheduler ... >>> >>> Now when I scale to multiple nodes problems with default MPI behaviour >>> starts. For example lets assume I have 2 nodes with 8 cpu cores each. I >>> therefore set up a machine file in the following way: >>> >>> s01 slots=1 >>> s02 slots=1 >>> >>> and start the node schedulers in the following way: >>> mpirun --np 2 --machinefile machinefile ./scheduler ... >>> >>> This allocates the processes correctly, now the problem starts when I >>> invoke MPI_Spawn. basically MPI spawn also uses the informations from the >>> machinefile and if 4 MPI processes are spawned 2 are allocated in s01 and 2 >>> on s02. What I want is to allocate the processes always in the same node. >>> >>> I tried to do this by specifying an MPI_Info object which is then passed to >>> the MPI_Spawn routine. I tried to set the "host" property to the hostname >>> of the machine where the scheduler is running but this didn't help. >>> >>> Unfortunately there is very little documentation on this. >>> >>> Thanks for the help, >>> Simone >>> _______________________________________________ >>> users mailing list >>> us...@open-mpi.org >>> http://www.open-mpi.org/mailman/listinfo.cgi/users >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users >
