Difference between revisions of "R MPI Example"

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[[R|back to the main R page]]
 
[[R|back to the main R page]]
  
Example of using the parallel module to run MPI jobs under Rmpi.
+
Example, of using the parallel module to run MPI jobs under SLURM with Rmpi library.
  
{{#fileAnchor: rmpi_test.R}}
+
<pre>
Download raw source of the [{{#fileLink: rmpi_test.R}} rmpi_test.R] file.
 
<source lang=bash>
 
 
# Load the R MPI package if it is not already loaded.
 
# Load the R MPI package if it is not already loaded.
 
if (!is.loaded("mpi_initialize")) {
 
if (!is.loaded("mpi_initialize")) {
 
     library("Rmpi")
 
     library("Rmpi")
 
     }
 
     }
                                                                               
+
 
# Spawn as many slaves as possible
+
ns <- mpi.universe.size() - 1
mpi.spawn.Rslaves()
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mpi.spawn.Rslaves(nslaves=ns)
                                                                               
+
#
 
# In case R exits unexpectedly, have it automatically clean up
 
# In case R exits unexpectedly, have it automatically clean up
 
# resources taken up by Rmpi (slaves, memory, etc...)
 
# resources taken up by Rmpi (slaves, memory, etc...)
 
.Last <- function(){
 
.Last <- function(){
    if (is.loaded("mpi_initialize")){
+
      if (is.loaded("mpi_initialize")){
        if (mpi.comm.size(1) > 0){
+
          if (mpi.comm.size(1) > 0){
            print("Please use mpi.close.Rslaves() to close slaves.")
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              print("Please use mpi.close.Rslaves() to close slaves.")
            mpi.close.Rslaves()
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              mpi.close.Rslaves()
        }
+
          }
        print("Please use mpi.quit() to quit R")
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          print("Please use mpi.quit() to quit R")
        .Call("mpi_finalize")
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          .Call("mpi_finalize")
    }
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      }
 
}
 
}
 
 
# Tell all slaves to return a message identifying themselves
 
# Tell all slaves to return a message identifying themselves
 +
mpi.bcast.cmd( id <- mpi.comm.rank() )
 +
mpi.bcast.cmd( ns <- mpi.comm.size() )
 +
mpi.bcast.cmd( host <- mpi.get.processor.name() )
 
mpi.remote.exec(paste("I am",mpi.comm.rank(),"of",mpi.comm.size()))
 
mpi.remote.exec(paste("I am",mpi.comm.rank(),"of",mpi.comm.size()))
 +
 +
# Test computations
 +
x <- 5
 +
x <- mpi.remote.exec(rnorm, x)
 +
length(x)
 +
x
  
 
# Tell all slaves to close down, and exit the program
 
# Tell all slaves to close down, and exit the program
mpi.close.Rslaves()
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mpi.close.Rslaves(dellog = FALSE)
 
mpi.quit()
 
mpi.quit()
</source>
+
</pre>
 +
 
 +
 
 +
Example job script using rmpi_test.R script.
 +
 
 +
<pre>
 +
#!/bin/sh
 +
#SBATCH --job-name=mpi_job_test # Job name
 +
#SBATCH --mail-type=END,FAIL # Mail events (NONE, BEGIN, END, FAIL, ALL)
 +
#SBATCH --mail-user=ENTER_YOUR_EMAIL_HERE # Where to send mail
 +
#SBATCH --cpus-per-task=1 # Number of cores per MPI rank
 +
#SBATCH --nodes=2 #Number of nodes
 +
#SBATCH --ntasks=8 # Number of MPI ranks
 +
#SBATCH --ntasks-per-node=4 #How many tasks on each node
 +
#SBATCH --ntasks-per-socket=2 #How many tasks on each CPU or socket
 +
#SBATCH --distribution=cyclic:cyclic #Distribute tasks cyclically on nodes and sockets
 +
#SBATCH --mem-per-cpu=1gb # Memory per processor
 +
#SBATCH --time=00:05:00 # Time limit hrs:min:sec
 +
#SBATCH --output=mpi_test_%j.out # Standard output and error log
 +
pwd; hostname; date
 +
 
 +
echo "Running example Rmpi script. Using $SLURM_JOB_NUM_NODES nodes with $SLURM_NTASKS
 +
tasks, each with $SLURM_CPUS_PER_TASK cores."
 +
module purge; module load gcc/9 openmpi rmpi
 +
 
 +
srun --mpi=pmi2 Rscript /data/training/SLURM/rmpi_test.R
 +
 
 +
date
 +
</pre>
 +
 
 +
For rmpi/4.0 module the following command will work
 +
 
 +
mpiexec -n ${SLURM_NTASKS} Rscript rmpi_test.R
 +
 
 +
 
 +
Link the /apps/rmpi/conf/Rprofile as .Rprofile in the current directory configuration file that must be placed in the working directory if the rmpi module doesn't add a symlink automatically.
 +
 
 +
<pre>
 +
ln -s /apps/rmpi/conf/Rprofile .Rprofile
 +
</pre>

Revision as of 13:54, 30 September 2020

back to the main R page

Example, of using the parallel module to run MPI jobs under SLURM with Rmpi library.

# Load the R MPI package if it is not already loaded.
if (!is.loaded("mpi_initialize")) {
    library("Rmpi")
    }

ns <- mpi.universe.size() - 1
mpi.spawn.Rslaves(nslaves=ns)
#
# In case R exits unexpectedly, have it automatically clean up
# resources taken up by Rmpi (slaves, memory, etc...)
.Last <- function(){
       if (is.loaded("mpi_initialize")){
           if (mpi.comm.size(1) > 0){
               print("Please use mpi.close.Rslaves() to close slaves.")
               mpi.close.Rslaves()
           }
           print("Please use mpi.quit() to quit R")
           .Call("mpi_finalize")
       }
}
# Tell all slaves to return a message identifying themselves
mpi.bcast.cmd( id <- mpi.comm.rank() )
mpi.bcast.cmd( ns <- mpi.comm.size() )
mpi.bcast.cmd( host <- mpi.get.processor.name() )
mpi.remote.exec(paste("I am",mpi.comm.rank(),"of",mpi.comm.size()))

# Test computations
x <- 5
x <- mpi.remote.exec(rnorm, x)
length(x)
x

# Tell all slaves to close down, and exit the program
mpi.close.Rslaves(dellog = FALSE)
mpi.quit()


Example job script using rmpi_test.R script.

#!/bin/sh
#SBATCH --job-name=mpi_job_test # Job name
#SBATCH --mail-type=END,FAIL # Mail events (NONE, BEGIN, END, FAIL, ALL)
#SBATCH --mail-user=ENTER_YOUR_EMAIL_HERE # Where to send mail	
#SBATCH --cpus-per-task=1 # Number of cores per MPI rank 
#SBATCH --nodes=2 #Number of nodes
#SBATCH --ntasks=8 # Number of MPI ranks
#SBATCH --ntasks-per-node=4 #How many tasks on each node
#SBATCH --ntasks-per-socket=2 #How many tasks on each CPU or socket
#SBATCH --distribution=cyclic:cyclic #Distribute tasks cyclically on nodes and sockets
#SBATCH --mem-per-cpu=1gb # Memory per processor
#SBATCH --time=00:05:00 # Time limit hrs:min:sec
#SBATCH --output=mpi_test_%j.out # Standard output and error log
pwd; hostname; date

echo "Running example Rmpi script. Using $SLURM_JOB_NUM_NODES nodes with $SLURM_NTASKS 
tasks, each with $SLURM_CPUS_PER_TASK cores."
module purge; module load gcc/9 openmpi rmpi

srun --mpi=pmi2 Rscript /data/training/SLURM/rmpi_test.R

date

For rmpi/4.0 module the following command will work

mpiexec -n ${SLURM_NTASKS} Rscript rmpi_test.R


Link the /apps/rmpi/conf/Rprofile as .Rprofile in the current directory configuration file that must be placed in the working directory if the rmpi module doesn't add a symlink automatically.

ln -s /apps/rmpi/conf/Rprofile .Rprofile