Compile and execute CLaMS programs on JUROPA

Compiler

To use the Intel MPI compiler the following command will be necessary:

• module load parastation/intel 

Compilation

All used libraries and module files are linked to:

• /lustre/jhome4/jicg11/jicg1108/clams_lib
  /lustre/jhome4/jicg11/jicg1108/clams_mod

The CLaMS makefiles are adjusted for compilation of CLaMS programs on JUROPA with the Intel compiler (mkincl/config/config.Linux_ifc).

The netCDF version 3.6.3 is used. For using netCDF 4 see Used Libraries (netCDF3/netCDF4).

The CLaMS programs can be compiled with:

•    1 gmake useComp=ifc [useMPI=true] progname
  

Create batch script

Write a batch script including the mpiexec command for the just compiled executable:

•    1 #!/bin/bash -x
     2 #MSUB -l nodes=<no of nodes>:ppn=<no of procs/node>
     3 #MSUB -l walltime=<hh:mm:ss>
     4 #MSUB -e <full path for error file>
     5 #MSUB -o <full path for output file>
     6 #MSUB -M <mail-address>
     7 #      official mail address
     8 #MSUB -m n|a|b|e
     9 #      send mail: never, on abort, beginning or end of job
    10 
    11 ### start of jobscript
    12 cd $PBS_O_WORKDIR
    13 echo "workdir: $PBS_O_WORKDIR"
    14 NP=$(cat $PBS_NODEFILE | wc -l) # nodes*ppn
    15 echo "running on $NP cpus ..."
    16 mpiexec -np $NP <executable>
  

Job Limits

Batch jobs

• max. number of nodes: 256 (default: 1)
• max. wall-clock time: 12 hours (default: 30 min)

Interactive jobs:

• max. number of nodes: 2 (default: 1)
• max. wall-clock time: 30 min (default: 10 min)

Submit job

Submit the job with:

• msub <jobscript>

On success msub returns the job ID of the submitted job.

Useful commands

• checkjob -v <jobid>
  get detailed information about a job

• showq [r]
  show status of all (running) jobs

• canceljob <jobid>
  cancel a job

• mjobctl -q starttime <jobid>
  show estimated starttime of specified job

• mjobctl --help
  show detailed information about this command

Problems with timeouts using MPI

Currently jobs requesting > 128 nodes ( >1024 cores) fail with PMI barrier timeouts. This is caused by a problem in the ParaStation process management which could not be fixed yet. As a workaround ParTec recommends the setting of the following environment variables in the job script of large MPI applications:

  export __PSI_LOGGER_TIMEOUT=3600  
  export PMI_BARRIER_TMOUT=1800  

just before the 'mpiexec' call. Similar problems have been observed on workstations as well.

Interactive Session

• Allocate interactive partition with X11 forwarding:

  msub -I -X -l nodes=#:ppn=8

  possible number of nodes: 1 or 2
• Start your applications
• Deallocate interactive partition with:

  exit