MP1: Running MPI Tasks on the Grid Appliance¶

Set Up and Submit MPI Jobs¶

1. First you will build a local installation of MPI on your appliance from source. Use the following commands (note that it will take a few minutes to build MPI). The “-m32” option allows a 64-bit machine to submit MPI jobs to 32-bit machines.

   su griduser
   cd ~/examples/mpi
   ./setup.sh -m32
   

2. Compile the “Hello World” example using the MPI cc compiler you just built in the previous step. (Note: This example builds a 32-bit binary with the “-m32” option):

   /mnt/local/mpich2/bin/mpicc -m32 -o HelloWorld HelloWorld.c
   

3. Before proceeding, check that your machine is connected to the public pool by using ``condor_status`` command. You may need to wait for a few minutes before it becomes fully operational.

4. Submit the “HelloWorld” program to run on 2 nodes:

   ./mpi_submit.py -n 2 HelloWorld
   

5. If all goes well, you will see an output similar to the output below; if an error occurs and the MPI ring fails to start, you can retry the command above.

   griduser@C111197176:~/examples/mpi$ ./mpi_submit.py -n 2 HelloWorld
   serv ipop ip = 5.111.197.176
   submit condor with file tmpo21uIeMh/submit_mpi_vanilla_o21uIeMh
   Submitting job(s).
   Logging submit event(s).
   1 job(s) submitted to cluster 5.
   Waiting for 1 workers to response .... finished
   
   host list:
   ['C079184183', '1', 'cndrusr1', '45556', '/var/lib/condor/execute/dir_2824']
   
   MPD trace:
   C111197176_60625 (5.111.197.176)
   C079184183_43364 (5.79.184.183)
   
   Processor 0 of 2: Hello World!
   Processor 1 of 2: Hello World!