...

This section offers guidelines on setting up an environment for building and running application software on LANTA.

1.1 HPE Cray Programming Environment

...

GPU acceleration

For building an application with GPU acceleration, users can use either PrgEnv-nvhpc, cudatoolkit/<version> or nvhpc-mixed. For simplicity, we recommend using PrgEnv-nvhpc.

Build target

To enable optimizations that depend on the hardware architecture of LANTA, the following modules should be loaded together with PrgEnv.

...

Module name

...

Hardware target

...

Note

...

craype-x86-milan

...

AMD EPYC Milan (x86)

...

-

...

craype-accel-nvidia80

...

NVIDIA A100

...

Load after PrgEnv-nvhpc, cudatoolkit or nvhpc-mixed

Cray optimized libraries

Most Cray optimized libraries become accessible only after loading a PrgEnv, ensuring compatibility with the selected compiler suite. Additionally, some libraries, such as NetCDF, require loading other specific libraries first. Below is the hierarchy of commonly used cray-* modules.

...

module purge
module load craype-x86-milan
module load PrgEnv-intel
module load cray-hdf5-parallel
module load cray-netcdf-hdf5parallel
module list
# Without version specified, the latest version will be loaded.

CPE version

To ensure backward compatibility after a system upgrade, it is recommended to fix the Cray Programming Environment version using either cpe/<version> or cpe-cuda/<version>. Otherwise, the most recent version will be loaded by default.

1.2 ThaiSC pre-built modules

For user convenience, we provide several shared modules of some widely used software and libraries. These modules were built on top of the HPE Cray Programming Environment, using the CPE toolchain.

CPE toolchain

A CPE toolchain module is a bundle of craype-x86-milan, PrgEnv-<compiler> and cpe-cuda/<version>. The module is defined as a toolchain for convenience and for use with EasyBuild, the framework used for installing most ThaiSC modules.

...

...

CPE toolchain

...

Note

...

cpeGNU/23.03

...

GCC 11.2.0

...

cpeCray/23.03

...

CCE 15.0.1

...

cpeIntel/23.03

...

Deprecated and hidden. It will be removed in the future.

...

cpeIntel/23.09

...

Intel Compiler 2023.1.0

ThaiSC modules

All ThaiSC modules are located at the same module path, so there is no module hierarchy. Executing module avail on LANTA will display all available ThaiSC modules. For a more concise list, you can use module overview, then, use module whatis <name> or module help <name> to learn more about a specific module.

Users can readily use ThaiSC modules and CPE toolchains to build their applications. Some popular application software are pre-installed as well, for more information, refer to Applications usage.

--------------------------------- /opt/cray/pe/lmod/modulefiles/core ---------------------------------
PrgEnv-aocc   (2)   cce          (3)   cray-libpals (3)   craypkg-gen   (2)   nvhpc          (2)
PrgEnv-cray   (2)   cpe-cuda     (3)   cray-libsci  (3)   cudatoolkit   (6)   nvidia         (2)
PrgEnv-gnu    (2)   cpe          (3)   cray-mrnet   (2)   gcc           (3)   papi           (3)
PrgEnv-intel  (2)   cray-R       (2)   cray-pals    (3)   gdb4hpc       (3)   perftools-base (3)
PrgEnv-nvhpc  (2)   cray-ccdb    (2)   cray-pmi     (3)   intel-classic (2)   sanitizers4hpc (2)
PrgEnv-nvidia (2)   cray-cti     (5)   cray-python  (2)   intel-oneapi  (2)   valgrind4hpc   (3)
aocc          (2)   cray-dsmml   (1)   cray-stat    (2)   intel         (2)
atp           (3)   cray-dyninst (2)   craype       (3)   iobuf         (1)

--------------------------------- /opt/

cray/

pe/

lmod/

modulefiles/

craype-targets/

default ----------------------------------
craype-x86-milan   

     (1)     craype-accel-nvidia80   (1)      

.

.

.

 other modules 

..

.

GPU acceleration

For building an application with GPU acceleration, users can use either PrgEnv-nvhpc, cudatoolkit/<version> or nvhpc-mixed. We recommend using PrgEnv-nvhpc for completeness.

Build target

To enable optimizations that depend on the hardware architecture of LANTA, the following modules should be loaded together with PrgEnv.

Cray optimized libraries

Most Cray optimized libraries become accessible only after loading a PrgEnv, ensuring compatibility with the selected compiler suite. Additionally, some libraries, such as NetCDF, require loading other specific libraries first. Below is the hierarchy of commonly used cray-* modules.

...

module purge
module load craype-x86-milan
module load PrgEnv-intel
module load cray-hdf5-parallel
module load cray-netcdf-hdf5parallel
module list
# Without version specified, the latest version will be loaded.

CPE version

To ensure backward compatibility after a system upgrade, it is recommended to fix the Cray Programming Environment version using either cpe/<version> or cpe-cuda/<version>. Otherwise, the most recent version will be loaded by default.

1.2 ThaiSC pre-built modules

For user convenience, we provide several shared modules of some widely used software and libraries. These modules were built on top of the HPE Cray Programming Environment, using the CPE toolchain.

CPE toolchain

A CPE toolchain module is a bundle of craype-x86-milan, PrgEnv-<compiler> and cpe-cuda/<version>. The module is defined as a toolchain for convenience and for use with EasyBuild, the framework used for installing most ThaiSC modules.

ThaiSC modules

All ThaiSC modules are located at the same module path, so there is no module hierarchy. Executing module avail on LANTA will display all available ThaiSC modules. For a more concise list, you can use module overview, then, use module spider <name> to learn more about each specific module.

Users can readily use ThaiSC modules and CPE toolchains to build their applications. Some popular application software are pre-installed as well, for more information, refer to Applications usage.

username@lanta-xname:~> module overview
--------------------------------- /lustrefs/disk/modules/easybuild/modules/all ---------------------------------
ADIOS2        (2)   GATK                  (1)   NASM            (1)    VASP/6.3.2-NVHPC-gpu_vtstTcl          (2)    Boost/1.79.0-cpeGNU-23.03groff         (2)
ATK           (2)   GDAL   VCFtools/0.1.16-cpeGNU-23.03    Boost/1.81.0-cpeGNU-23.03           (2)   NLopt            WPS/4.4-DM-cpeCray-23.03(2)   Tk           (D2)    Boost/1.81.0-cpeIntel-23.09hwloc         (1)
Amber         (1)   GEOS   WPS/4.5-DM-cpeIntel-23.09    Boost/1.82.0-cpeCray-23.03           (2)   Nextflow (D)       WRF/4.4.2-DMSM-cpeCray-23.03(2)   Trimmomatic  Bowtie/1.3.1-cpeGNU-23.03(1)   intltool      (1)
Apptainer      (1)   GLM        WRFchem/4.5.1-DM-cpeIntel-23.09    Bowtie2/2.5.1-cpeGNU-23.03       (2)   Ninja           (1)    XZ/5.4.3-cpeCray-23.03UDUNITS2     C-Blosc2/2.10.5-cpeIntel-23.09(1)   jbigkit       (2)
Armadillo     (2)   GLib  XZ/5.4.3-cpeGNU-23.03    CFITSIO/4.2.0-cpeIntel-23.09            (2)   OSPRay        XZ/5.4.3-cpeIntel-23.09  (2)   VASP         (D3)    CGAL/5.5.2-cpeCray-23.03libGLU        (2)
AutoDock-vina (1)   GMP                   (3)   OpenCASCADE     Xerces-C++/3.2.4

module purge
module load Boost/1.81.0-cpeGNU-23.03
echo ${CPATH}
echo ${LIBRARY_PATH}
echo ${LD_LIBRARY_PATH}

2. Building an application software

After an appropriate environment is loaded, this section provides guidelines on how to use it to build an application software on LANTA.

2.1 Compiler wrapper

...

<wrapper> command

...

Description

...

Manual

...

In substitution for

...

cc

...

C compiler wrapper

...

man cc or cc --help

...

mpicc / mpiicc

...

CC

...

C++ compiler wrapper

...

man CC or CC --help

...

mpic++ / mpiicpc

...

ftn

...

Fortran compiler wrapper

...

man ftn or ftn --help

...

mpif90 / mpiifort

The Cray compiler wrappers, namely, cc, CC and ftn, become available after loading any PrgEnv-<compiler> or CPE toolchain. Upon being invoked, the wrapper will pass relevant information about the cray-* libraries, loaded in the current environment, to the underlying <compiler> to compile source code. It is recommended to use these wrappers for building MPI applications with the native Cray MPICH library cray-mpich.

Adding -craype-verbose to the wrapper when compiling a source file will display the final command executed. To see what will be added before compiling, try <wrapper> --cray-print-opts=all.

module purge
module load GDAL/3.6.4-cpeIntel-23.09
cc --cray-print-opts=all

(2)   VCFtools     (1)   libaec        (2)
Autoconf      (1)   GObject-Introspection (2)   OpenEXR         (2)   WPS          (2)   libdeflate    (2)
Automake      (1)   GROMACS               (2)   OpenFOAM        (2)   WRF          (1)   libdrm        (2)
Autotools     (1)   GSL                   (3)   OpenJPEG        (2)   WRFchem      (2)   libepoxy      (2)
BCFtools      (1)   Gaussian              (1)   OpenMPI         (1)   Wayland      (2)   libffi        (1)
BEDTools      (1)   GenericIO             (2)   OpenSSL         (1)   X11          (2)   libgeotiff    (2)
BLAST+        (1)   Gmsh                

(1)

   OpenTURNS       

(2)   XZ    

(3) 

libglvnd 

 (2)
BLASTDB       

(1)   Go      

        (1)   PCRE            

(1)

   Xerces-C++   

(1) 

libiconv  

2.2 Build tools

Several tools exist to help us build large and complex programs. Among them, GNU make and CMake are commonly used. The developer team for each software chooses what build tool they will support. Therefore, it is important to thoroughly read the software documentation. For some software, users might need to additionally load the latest CMake or Autotools modules on the system (e.g., module load CMake/3.26.4).

There are three general stages in building a program using a build tool: configure, make and make install. For more information, see Basic Installation.

Build tools typically detect compilers through environment variables such as CC, CXX, and FC at the configure stage. Therefore, setting these variables before running configure should be sufficient to make the tool use the Cray compiler wrappers.

export CC=cc CXX=CC FC=ftn F77=ftn F90=ftn
# ./configure --prefix=<your-install-location> ...
# or 
# cmake -DCMAKE_INSTALL_PREFIX=<your-install-location> ...

Nevertheless, if the CMake cache is not clean, you might need to explicitly use:

cmake -DCMAKE_C_COMPILER=cc -DCMAKE_CXX_COMPILER=CC -DCMAKE_Fortran_COMPILER=ftn -DCMAKE_INSTALL_PREFIX=<your-install-location> ...

We encourage users to manually specify the installation path using --prefix= or -DCMAKE_INSTALL_PREFIX= as shown above. This path can be within your project home, such as /project/ltXXXXXX-YYYY/<software-name>, allowing you to manage permissions and share the installed software with your project members. By default on LANTA, your team will be able to read and execute your software but cannot make any changes inside the directory you own.

After these steps, you should be able to execute make and make install, then build your software as you would on any other system.

(2)
BWA           (1)   HDF-EOS               (2)   PCRE2           (1)   Yasm         (1)   libjpeg-turbo (3)
BamTools      (1)   HDF                   (2)   PDAL            (1)   arpack-ng    (2)   libpciaccess  (2)
Beast         (1)   HTSlib                (1)   PETSc           (2)   assimp       (2)   libpng        (3)
Bison         (1)   HYPRE                 (2)   PROJ            (2)   at-spi2-atk  (2)   libreadline   (2)
Blosc         (2)   HarfBuzz              (2)   Pango           (2) 

2.3 Related topics

Local module & EasyBuild

A separate page is dedicated for explaining how to manage and install local modules in the user’s home/project paths using EasyBuild → Local module & EasyBuild (In progress)

Useful compiler flags

• Intel oneAPI (In progress)

Other approach

• Miniconda

• Apptainer / Singularity

3. Running the software

Every main application software must run on compute/gpu/memory nodes. The recommended approach is to write a job script and send it to Slurm scheduler through sbatch command.

3.1 Writing a job script

#!/bin/bash
#SBATCH -p gpu         at-spi2-core (2)   libtirpc      (2)
Boost         (4)   ICU                   (3)   ParFlow         (1)   aws-ofi-nccl (1)   libtool       (1)
Bowtie        (1)   Imath         # Partition #SBATCH -N 1    (2)   ParMETIS        (2)   beagle-lib # Number of(1) nodes #SBATCH --gpus=4libunwind     (2)
Bowtie2       (1)  # NumberJasPer of GPU cards #SBATCH --ntasks=4            (3)   ParaView        (1)   binutils     (1)   libxml2       (3)
Brotli        (2)   Java                  (2)   ParallelIO      # Number of MPI processes
#SBATCH --cpus-per-task=16     # Number of OpenMP threads per MPI process
#SBATCH -t 5-00:00:00          # Job runtime limit
#SBATCH -A ltXXXXXX            # Billing account 
# #SBATCH -J <JobName>           # Job name

module purge
# --- Load necessary modules ---
module load <...>
module load <...>

# --- Add software to Linux search paths ---
export PATH=<software-bin-path>:${PATH}
export LD_LIBRARY_PATH=<software-lib/lib64-path>:${LD_LIBRARY_PATH}
# export PYTHONPATH=<software-python-site-packages>:${PYTHONPATH}
# source <your-software-specific-script>

# --- (Optional) Set related environment variables ---
# export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK}         # MUST specify --cpus-per-task above

# --- Run the software ---
# srun <srun-options> ./<software>
# or
# ./<software>

The above job script template consists of five sections:

...

It should be noted that Slurm sbatch options only define and request computing resources that can be used inside a job script. The actual resources used by a software/executable can be different depending on how it will be invoked/issued (see Stage 5).

2. Loading modules
It is advised to load every module used when installing the software in the job script, although build dependencies such as CMake, Autotools, and binutils can be omitted. Additionally, those modules should be of the same version as when they were used to compile the program.

3. Adding software paths
The Linux OS will not be able to find your program if it is not in its search paths. The commonly used ones are namely PATH (for executable/binary), LD_LIBRARY_PATH (for shared library), and PYTHONPATH (for python packages). Users MUST append or prepend them using syntax such as export PATH=<software-bin-path>:${PATH}, otherwise, prior search paths added by module load and others will disappear.
If <your-install-location> is where your software is installed, then putting the below commands in your job script should be sufficient in most cases.

export PATH=<your-install-location>/bin(1)   bzip2        (3)   lz4           (3)
C-Blosc2      (2)   KaHIP                 (2)   Perl            (2)   cURL         (1)   minimap2      (1)
CFITSIO       (2)   LAME                  (1)   PostgreSQL      (2)   cairo        (2)   nccl          (1)
CGAL          (2)   LLVM                  (1)   QuantumESPRESSO (2)   canu         (1)   ncurses       (2)
CMake         (2)   LMDB                  (1)   RAxML-NG        (1)   cpeCray      (1)   nlohmann_json (1)
CrayNVHPC     (1)   LibTIFF               (2)   SAMtools        (1)   cpeGNU       (1)   numactl       (1)
DB            (2)   M4                    (1)   SCOTCH          (2)   cpeIntel     (1)   pixman        (1)
DBus          (1)   MAFFT                 (1)   SDL2            (2)   ecCodes      (2)   pkgconf       (1)
ESMF          (2)   METIS                 (2)   SLEPc           (2)   expat        (2)   tbb           (1)
EasyBuild     (1)   MPC                   (2)   SPAdes          (1)   flex         (1)   termcap       (1)
Eigen         (1)   MPFR                  (2)   SQLite          (2)   fontconfig   (2)   x264          (1)
FDS           (1)   MUMPS                 (3)   SWIG            (3)   freetype     (2)   x265          (1)
FFmpeg        (2)   Mako                  (2)   SYCL            (1)   gettext      (1)   xorg-macros   (2)
FastQC        (1)   Mamba                 (1)   SZ              (2)   git-lfs      (1)   xprop         (2)
FortranGIS    (2)   Mesa                  (2)   SpectrA         (1)   googletest   (1)   zfp           (2)
FreeXL        (2)   Meson                 (2)   SuiteSparse     (2)   gperf        (1)   zlib          (2)
FriBidi       (2)   MrBayes               (1)   SuperLU_DIST    (2)   gperftools   (2)   zstd          (3)

module purge
module load Boost/1.81.0-cpeGNU-23.03
echo ${CPATH}
echo ${LIBRARY_PATH}
echo ${LD_LIBRARY_PATH}

...

2. Building an application software

After an appropriate environment is loaded, this section provides guidelines on how to use it to build an application software on LANTA.

2.1 Compiler wrapper

The Cray compiler wrappers, namely, cc, CC and ftn, become available after loading any PrgEnv-<compiler> or CPE toolchain. Upon being invoked, the wrapper will pass relevant information about the cray-* libraries, loaded in the current environment, to the underlying <compiler> to compile source code. It is recommended to use these wrappers for building MPI applications with the native Cray MPICH library cray-mpich.

Adding -craype-verbose to the wrapper when compiling a source file will display the final command executed. To see what will be added before compiling, try <wrapper> --cray-print-opts=all.

module purge
module load GDAL/3.6.4-cpeIntel-23.09
cc --cray-print-opts=all

# Create the source code
cat << Eof > HelloWorld.c
#include <stdio.h>
#include <mpi.h>
#include <omp.h>

int main(){
    int rank, thread ;
    omp_lock_t io_lock ;
    omp_init_lock(&io_lock);

    MPI_Init(NULL, NULL);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    
    #pragma omp parallel private(thread)
    {
        thread = omp_get_thread_num();
        omp_set_lock(&io_lock);
        printf("HelloWorld from rank %d thread %d \n", rank, thread);
        omp_unset_lock(&io_lock);
    }

    omp_destroy_lock(&io_lock);
    MPI_Finalize();
    
return 0; }
Eof

module purge
module load craype-x86-milan
module load PrgEnv-intel
# or
# module load cpeIntel/23.09

# Compile the source file 'HelloWorld.c'
cc -craype-verbose -o hello.exe HelloWorld.c -fopenmp

# Run the program 
srun -p compute-devel -N1 -n4 -c2 hello.exe

# Create the source code
cat << Eof > HelloWorld.cpp
#include <iostream>
#include <mpi.h>
#include <omp.h>

int main(){
    int rank, thread ;
    omp_lock_t io_lock ;
    omp_init_lock(&io_lock);

    MPI_Init(nullptr,nullptr);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    
    #pragma omp parallel private(thread)
    {
        thread = omp_get_thread_num();
        omp_set_lock(&io_lock);
	    std::cout << "HelloWorld from rank " << rank << " thread " << thread << std::endl;
        omp_unset_lock(&io_lock);
    }

    omp_destroy_lock(&io_lock);
    MPI_Finalize();
    
return 0; }
Eof

module purge
module load craype-x86-milan
module load PrgEnv-intel
# or
# module load cpeIntel/23.09

# Compile the source file 'HelloWorld.cpp'
CC -craype-verbose -o hello.exe HelloWorld.cpp -fopenmp

# Run the program 
srun -p compute-devel -N1 -n4 -c2 hello.exe

# Create the source code
cat << Eof > HelloWorld.f90
program helloworld_mpi_omp
    use mpi
    use omp_lib

    implicit none
    integer :: rank, thread, provided, ierr
    integer(kind=omp_lock_kind) :: io_lock

    call omp_init_lock(io_lock)
    call MPI_Init(ierr)
    call MPI_Comm_rank(MPI_COMM_WORLD, rank, ierr)

    !\$omp parallel private(thread)
    thread = omp_get_thread_num()

    call omp_set_lock(io_lock)
    print *, 'HelloWorld from rank ', rank, ' thread ', thread
    call omp_unset_lock(io_lock)
    !\$omp end parallel

    call omp_destroy_lock(io_lock)
    call MPI_Finalize(ierr)

end program helloworld_mpi_omp
Eof
# Note: change !\$omp to !$omp if you type the above code by hand.

module purge
module load craype-x86-milan
module load PrgEnv-intel
# or
# module load cpeIntel/23.09

# Compile the source file 'HelloWorld.cpp'
ftn -craype-verbose -o hello.exe HelloWorld.f90 -fopenmp

# Run the program 
srun -p compute-devel -N1 -n4 -c2 hello.exe

2.2 Build tools

Several tools exist to help us build large and complex programs. Among them, GNU make and CMake are commonly used. The developer team for each software chooses what build tool they will support. Therefore, it is important to thoroughly read the software documentation. For some software, users might need to additionally load the latest CMake or Autotools modules on the system (e.g., module load CMake/3.26.4).

There are three general stages in building a program using a build tool: configure, make and make install. For more information, see Basic Installation.

Build tools typically detect compilers through environment variables such as CC, CXX, and FC at the configure stage. Therefore, setting these variables before running configure should be sufficient to make the tool use the Cray compiler wrappers.

export CC=cc CXX=CC FC=ftn F77=ftn F90=ftn
# ./configure --prefix=<your-install-location> ...
# or 
# cmake -DCMAKE_INSTALL_PREFIX=<your-install-location> ...

Nevertheless, if the CMake cache is not clean, you might need to explicitly use:

cmake -DCMAKE_C_COMPILER=cc -DCMAKE_CXX_COMPILER=CC -DCMAKE_Fortran_COMPILER=ftn -DCMAKE_INSTALL_PREFIX=<your-install-location> ...

We encourage users to manually specify the installation path using --prefix= or -DCMAKE_INSTALL_PREFIX= as shown above. This path can be within your project home, such as /project/ltXXXXXX-YYYY/<software-name>, allowing you to manage permissions and share the installed software with your project members. By default on LANTA, your team will be able to read and execute your software but cannot make any changes inside the directory you own.

After these steps, you should be able to execute make and make install, then build your software as you would on any other system.

module purge
module load cpeCray/23.03
module load NASM/2.16.01
module load CMake/3.26.4

wget https://github.com/libjpeg-turbo/libjpeg-turbo/releases/download/3.0.2/libjpeg-turbo-3.0.2.tar.gz
tar xzf libjpeg-turbo-3.0.2.tar.gz
cd libjpeg-turbo-3.0.2
PARENT_DIR=$(pwd)
mkdir build ; cd build

export CC=cc CXX=CC FC=ftn F77=ftn F90=ftn
# or, for verbosity,
#export CC="cc -craype-verbose" CXX="CC -craype-verbose" FC="ftn -craype-verbose" F77="ftn -craype-verbose" F90="ftn -craype-verbose"

cmake -DCMAKE_INSTALL_PREFIX=${PARENT_DIR}/cpeCray-23.03 -G"Unix Makefiles" -DWITH_JPEG8=1 ..
make
make install

cd ${PARENT_DIR}/cpeCray-23.03
ln -s ./lib64 ./lib               # Optional, but recommended

2.3 Related topics

• Local module & EasyBuild

• Intel C/C++ compiler flags

• Intel Fortran compiler flags

...

3. Running the software

Every main application software must run on compute/gpu/memory nodes. The recommended approach is to write a job script and send it to Slurm scheduler through sbatch command.

3.1 Writing a job script

#!/bin/bash
#SBATCH -p gpu                 # Partition
#SBATCH -N 1                   # Number of nodes
#SBATCH --gpus=4               # Number of GPU cards
#SBATCH --ntasks=4             # Number of MPI processes
#SBATCH --cpus-per-task=16     # Number of OpenMP threads per MPI process
#SBATCH -t 5-00:00:00          # Job runtime limit
#SBATCH -A ltXXXXXX            # Billing account 
# #SBATCH -J <JobName>         # Job name

module purge
# --- Load necessary modules ---
module load <...>
module load <...>

# --- Add software to Linux search paths ---
export PATH=<software-bin-path>:${PATH}
export LD_LIBRARY_PATH=<software-lib/lib64-path>:${LD_LIBRARY_PATH}
# export PYTHONPATH=<software-python-site-packages>:${PYTHONPATH}
# source <your-software-specific-script>

# --- (Optional) Set related environment variables ---
# export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK}         # MUST specify --cpus-per-task above

# --- Run the software ---
# srun <srun-options> ./<software>
# or
# ./<software>

The above job script template consists of five sections:

1. Slurm sbatch header

Mostly, Slurm sbatch options only define and request computing resources that can be used inside a job script. The actual resources used by a software/executable can be different depending on how it will be invoked/issued (see Stage 5), although these sbatch options are passed and become the default options for it. For GPU jobs, using either --gpus or --gpus-per-node to request GPUs at this stage will provide the most flexibility for the next stage, GPU binding.

If your application software only supports parallelization by multi-threading, then your software cannot utilize resources across nodes; in this case, therefore, -N, -n, --ntasks and --ntasks-per-node should be set to 1.

2. Loading modules
It is advised to load every module used when installing the software in the job script, although build dependencies such as CMake, Autotools, and binutils can be omitted. Additionally, those modules should be of the same version as when they were used to compile the program.

3. Adding software paths
The Linux OS will not be able to find your program if it is not in its search paths. The commonly used ones are namely PATH (for executable/binary), LD_LIBRARY_PATH (for shared library), and PYTHONPATH (for python packages). Users MUST append or prepend them using syntax such as export PATH=<software-bin-path>:${PATH}, otherwise, prior search paths added by module load and others will disappear.
If <your-install-location> is where your software is installed, then putting the below commands in your job script should be sufficient in most cases.

export PATH=<your-install-location>/bin:${PATH}
export LD_LIBRARY_PATH=<your-install-location>/lib:${LD_LIBRARY_PATH}
export LD_LIBRARY_PATH=<your-install-location>/lib64:${LD_LIBRARY_PATH}

Some of them can be omitted if there no such sub-directory when using ls <your-install-location>.

export PYTHONPATH=<your-install-location>/lib/python<Version>/site-packages:${PYTHONPATH}

bash   # You should check them in another bash shell

module purge
module load <...>
module load <...>

export PATH=<software-bin-path>:${PATH}
export LD_LIBRARY_PATH=

<software-

lib/lib64-path>:${LD_LIBRARY_PATH}
export 

PYTHONPATH=<software-python-site-packages>:${

Some of them can be omitted if there no such sub-directory when using ls <your-install-location>.

export PYTHONPATH=<your-install-location>/lib/python<Version>/site-packages:${PYTHONPATH}

...

• If some software dependencies were installed locally, their search paths should also be added.

• We do NOT recommend specifying these search paths in ~/.bashrc directly, as it could lead to library conflicts when having more than one main software.

• Some software provides a script to be sourced before using. In this case, sourcing it in your job script should be equivalent to adding its search paths manually by yourself.

When executing your program, if you encounter

• If 'xxx' is not a typo you can use command-not-found to lookup ..., then, your current PATH variable may be incorrect.

• xxx: error while loading shared libraries: libXXX.so: cannot open shared object file, then,

  • If libXXX.so seem to be related to your software, then you may set LD_LIBRARY_PATH variable in Step 3 incorrectly.

  • If libXXX.so seem to be from a module you used to build your software, then loading that module should fix the problem.

• ModuleNotFoundError: No module named 'xxx', then, your current PYTHONPATH may be incorrect.

Preliminary check could be performed on frontend node by doing something like

bash   # You should check them in another bash shell

module purge
module load <...>
module load <...>

export PATH=<software-bin-path>:${PATH}
export LD_LIBRARY_PATH=<software-lib/lib64-path>:${LD_LIBRARY_PATH}
export PYTHONPATH=<software-python-site-packages>:${PYTHONPATH}

<executable> --help
<executable> --version

exit

4. Setting environment variables
Some software requires additional environment variables to be set at runtime; for example, the path to the temporary directory. Parameters set by Slurm sbatch (see Slurm sbatch - output environment variables) could be utilized in setting up software-specific environment variables.
In addition, OMP_NUM_THREADS, OMP_STACKSIZE, ulimit -s unlimited are commonly set in a job script. An example is shown below.

export XXX_TMPDIR=/scratch/ltXXXXXX-YYYY/${SLURM_JOBID}
export OMP_STACKSIZE="32M"
export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK}
ulimit -s unlimited 

...

Usually, either srun, mpirun, mpiexec or aprun is required to run MPI programs. On LANTA, srun command MUST be used instead. The table below compares a few options of those commands.

...

Command

...

Total MPI processes

...

CPU per MPI process

...

MPI processes per node

...

srun

...

-n, --ntasks

...

-c, --cpus-per-task

...

--ntasks-per-node

...

mpirun/mpiexec

...

-n, -np

...

--map-by socket:PE=N

...

--map-by ppr:N:node

...

aprun

...

-n, --pes

...

-d, --cpus-per-pe

...

-N, --pes-per-node

There is usually no need to add options to srun since, by default, Slurm will automatically derive them from sbatch. However, we recommend explicitly adding GPU binding options such as --gpus-per-task or --ntasks-per-gpu according to your software specification to srun. Please visit Slurm srun for more details.

PYTHONPATH}

<executable> --help
<executable> --version

exit

4. Setting environment variables
Some software requires additional environment variables to be set at runtime; for example, the path to the temporary directory. Output environment variables set by Slurm sbatch (see Slurm sbatch - output environment variables) could be used to set software-specific parameters.
For application with OpenMP threading, OMP_NUM_THREADS, OMP_STACKSIZE, ulimit -s unlimited are commonly set in a job script. An example is shown below.

export XXX_TMPDIR=/scratch/ltXXXXXX-YYYY/${SLURM_JOBID}
export OMP_STACKSIZE="32M"
export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK}
ulimit -s unlimited 

5. Running your software

Usually, either srun, mpirun, mpiexec or aprun is required to run MPI programs. On LANTA, srun command MUST be used to launch MPI processes. The table below compares a few options of those commands.

There is usually no need to explicitly add option to srun since, by default, Slurm will automatically derive them from sbatch, with the exception of --cpus-per-task.

...

...

Example

• MiniWeather

Installation guide

• WRF (cpeCray DM+ cudatoolkitSM)

...

• WRF-Chem

• WPS

• WRFDA

Reference

...