Building Ascent

This page provides details on several ways to build Ascent from source.

For the shortest path from zero to Ascent, see Quick Start.

To build third party dependencies we recommend using uberenv which leverages Spack or Spack directly. We also provide info about building for known HPC clusters using uberenv. and a Docker example that leverages Spack.

Overview

Ascent uses CMake for its build system. Building Ascent creates two separate libraries:

• libascent : a version for execution on a single node
• libascent_mpi : a version for distributed-memory parallel

The CMake variable( ENABLE_MPI ON | OFF ) controls the building the parallel version of Ascent and included proxy-apps.

The build dependencies vary according to which pipelines and proxy-applications are desired. For a minimal build with no parallel components, the following are required:

• Conduit
• C++ compilers

We recognize that building on HPC systems can be difficult, and we have provide two separate build strategies.

• A spack based build
• Manually compile decencies using a CMake configuration file to keep compilers and libraries consistent

Most often, the spack based build should be attempted first. Spack will automatically download and build all the third party dependencies and create a CMake configuration file for Ascent. Should you encounter build issues that are not addressed here, please ask questions using our github issue tracker.

Build Dependencies

Ascent

• Conduit
• One or more runtimes

For Ascent, the Flow runtime is builtin, but for visualization functionality (filters and rendering), the VTK-h runtime is needed.

Conduit (Required)

• MPI
• Python + NumPy (Optional)
• HDF5 (Optional)
• Fortran compiler (Optional)

VTK-h (Optional)

• VTK-h:

  • VTK-m:
    • OpenMP (Optional)
    • CUDA 7.5+ (Optional)
    • MPI (Optional)

Note

When building VTK-m for use with VTK-h, VTK-m must be configured with rendering on, among other options. See the VTK-h spack package for details.

MFEM (Optional)

• MPI
• Metis
• Hypre

Getting Started

Clone the Ascent repo:

• From Github

git clone --recursive https://github.com/Alpine-DAV/ascent.git

--recursive is necessary because we are using a git submodule to pull in BLT (https://github.com/llnl/blt). If you cloned without --recursive, you can checkout this submodule using:

cd ascent
git submodule init
git submodule update

Configure a build:

config-build.sh is a simple wrapper for the cmake call to configure ascent. This creates a new out-of-source build directory build-debug and a directory for the install install-debug. It optionally includes a host-config.cmake file with detailed configuration options.

cd ascent
./config-build.sh

Build, test, and install Ascent:

cd build-debug
make -j 8
make test
make install

Build Options

Ascent’s build system supports the following CMake options:

• BUILD_SHARED_LIBS - Controls if shared (ON) or static (OFF) libraries are built. (default = ON)
• ENABLE_TESTS - Controls if unit tests are built. (default = ON)
• ENABLE_DOCS - Controls if the Ascent documentation is built (when sphinx and doxygen are found ). (default = ON)
• ENABLE_FORTRAN - Controls if Fortran components of Ascent are built. This includes the Fortran language bindings and Cloverleaf3D . (default = ON)
• ENABLE_PYTHON - Controls if the ascent python module and related tests are built. (default = OFF)

The Ascent python module will build for both Python 2 and Python 3. To select a specific Python, set the CMake variable PYTHON_EXECUTABLE to path of the desired python binary. The ascent python module requires the Conduit python module.

• ENABLE_OPENMP - Controls if the proxy-apps are configured with OpenMP. (default = OFF)
• ENABLE_MPI - Controls if parallel versions of proxy-apps and Ascent are built. (default = ON)

We are using CMake’s standard FindMPI logic. To select a specific MPI set the CMake variables MPI_C_COMPILER and MPI_CXX_COMPILER, or the other FindMPI options for MPI include paths and MPI libraries.

To run the mpi unit tests on LLNL’s LC platforms, you may also need change the CMake variables MPIEXEC and MPIEXEC_NUMPROC_FLAG, so you can use srun and select a partition. (for an example see: src/host-configs/chaos_5_x86_64.cmake)

Warning

Starting in CMake 3.10, the FindMPI MPIEXEC variable was changed to MPIEXEC_EXECUTABLE. FindMPI will still set MPIEXEC, but any attempt to change it before calling FindMPI with your own cached value of MPIEXEC will not survive, so you need to set MPIEXEC_EXECUTABLE [reference].

• CONDUIT_DIR - Path to an Conduit install (required).
• VTKM_DIR - Path to an VTK-m install (optional).
• HDF5_DIR - Path to a HDF5 install (optional).
• MFEM_DIR - Path to a MFEM install (optional).
• ADIOS_DIR - Path to a ADIOS install (optional).
• BLT_SOURCE_DIR - Path to BLT. (default = “blt”)

Defaults to “blt”, where we expect the blt submodule. The most compelling reason to override is to share a single instance of BLT across multiple projects.

Host Config Files

To handle build options, third party library paths, etc we rely on CMake’s initial-cache file mechanism.

cmake -C config_file.cmake

We call these initial-cache files host-config files, since we typically create a file for each platform or specific hosts if necessary.

The config-build.sh script uses your machine’s hostname, the SYS_TYPE environment variable, and your platform name (via uname) to look for an existing host config file in the host-configs directory at the root of the ascent repo. If found, it passes the host config file to CMake via the -C command line option.

cmake {other options} -C host-configs/{config_file}.cmake ../

You can find example files in the host-configs directory.

These files use standard CMake commands. CMake set commands need to specify the root cache path as follows:

set(CMAKE_VARIABLE_NAME {VALUE} CACHE PATH "")

It is possible to create your own configure file, and an boilerplate example is provided in /host-configs/boilerplate.cmake

Warning

If compiling all of the dependencies yourself, it is important that you use the same compilers for all dependencies. For example, different MPI and Fortran compilers (e.g., Intel and GCC) are not compatible with one another.

Building Ascent and Third Party Dependencies

We use Spack (http://spack.io) to help build Ascent’s third party dependencies on OSX and Linux.

Uberenv (scripts/uberenv/uberenv.py) automates fetching spack, building and installing third party dependencies, and can optionally install Ascent as well. To automate the full install process, Uberenv uses the Ascent Spack package along with extra settings such as Spack compiler and external third party package details for common HPC platforms.

Uberenv Options for Building Third Party Dependencies

uberenv.py has a few options that allow you to control how dependencies are built:

Option	Description	Default
–prefix	Destination directory	uberenv_libs
–spec	Spack spec	linux: %gcc osx: %clang
–spack-config-dir	Folder with Spack settings files	linux: (empty) osx: scripts/uberenv/spack_configs/darwin/
-k	Ignore SSL Errors	False
–install	Fully install conduit, not just dependencies	False
–run_tests	Invoke tests during build and against install	False

The -k option exists for sites where SSL certificate interception undermines fetching from github and https hosted source tarballs. When enabled, uberenv.py clones spack using:

git -c http.sslVerify=false clone https://github.com/llnl/spack.git

And passes -k to any spack commands that may fetch via https.

Default invocation on Linux:

python scripts/uberenv/uberenv.py --prefix uberenv_libs \
                                  --spec %gcc

Default invocation on OSX:

python scripts/uberenv/uberenv.py --prefix uberenv_libs \
                                  --spec %clang \
                                  --spack-config-dir scripts/uberenv/spack_configs/darwin/

The uberenv –install installs conduit@master (not just the development dependencies):

python scripts/uberenv/uberenv.py --install

To run tests during the build process to validate the build and install, you can use the --run_tests option:

python scripts/uberenv/uberenv.py --install \
                                  --run_tests

For details on Spack’s spec syntax, see the Spack Specs & dependencies documentation.

Compiler Settings for Third Party Dependencies

You can edit yaml files under scripts/uberenv/spack_config/{platform} or use the –spack-config-dir option to specify a directory with compiler and packages yaml files to use with Spack. See the Spack Compiler Configuration and Spack System Packages documentation for details.

For OSX, the defaults in spack_configs/darwin/compilers.yaml are X-Code’s clang and gfortran from https://gcc.gnu.org/wiki/GFortranBinaries#MacOS.

Note

The bootstrapping process ignores ~/.spack/compilers.yaml to avoid conflicts and surprises from a user’s specific Spack settings on HPC platforms.

When run, uberenv.py checkouts a specific version of Spack from github as spack in the destination directory. It then uses Spack to build and install Conduit’s dependencies into spack/opt/spack/. Finally, it generates a host-config file {hostname}.cmake in the destination directory that specifies the compiler settings and paths to all of the dependencies.

Building with Uberenv on Known HPC Platforms

To support testing and installing on common platforms, we maintain sets of Spack compiler and package settings for a few known HPC platforms. Here are the commonly tested configurations:

System	OS	Tested Configurations (Spack Specs)
pascal.llnl.gov	Linux: TOSS3	%gcc %gcc~shared
lassen.llnl.gov	Linux: BlueOS	%clang@coral~python~fortran
cori.nersc.gov	Linux: SUSE / CNL	%gcc

See scripts/spack_build_tests/ for the exact invocations used to test on these platforms.

Building Third Party Dependencies for Development

You can use bootstrap-env.sh (located at the root of the ascent repo) to help setup your development environment on OSX and Linux. This script uses scripts/uberenv/uberenv.py, which leverages Spack (https://spack.io/) to build the external third party libraries and tools used by Ascent. Fortran support in is optional, dependencies should build without fortran. After building these libraries and tools, it writes an initial host-config file and adds the Spack built CMake binary to your PATH, so can immediately call the config-build.sh helper script to configure a ascent build.

#build third party libs using spack
source bootstrap-env.sh

#copy the generated host-config file into the standard location
cp uberenv_libs/`hostname`*.cmake host-configs/

# run the configure helper script
./config-build.sh

# or you can run the configure helper script and give it the
# path to a host-config file
./config-build.sh uberenv_libs/`hostname`*.cmake

Building with Spack

Currently, we maintain our own fork of Spack for stability. As part of the uberenv python script, we automatically clone our Spack fork.

Warning

Installing Ascent from the Spack master branch will most likely fail. We build and test spack installations with uberenv.py.

To install Ascent with all options (and also build all of its dependencies as necessary) run:

spack install ascent

To build and install Ascent with CUDA support:

spack install ascent+cuda

The Ascent Spack package provides several variants that customize the options and dependencies used to build Ascent:

Variant	Description	Default
shared	Build Ascent as shared libraries	ON (+shared)
cmake	Build CMake with Spack	ON (+cmake)
python	Enable Ascent Python support	ON (+python)
mpi	Enable Ascent MPI support	ON (+mpi)
vtkh	Enable Ascent VTK-h support	ON (+vtkh)
tbb	Enable VTK-h TBB support	ON (+tbb)
cuda	Enable VTK-h CUDA support	OFF (~cuda)
doc	Build Ascent’s Documentation	OFF (~doc)
doc	Enable MFEM support	OFF (~mfem)

Variants are enabled using + and disabled using ~. For example, to build Conduit with the minimum set of options (and dependencies) run:

spack install ascent+cuda~python~docs

See Spack’s Compiler Configuration to customize which compiler settings.

Using system installs of dependencies with Spack

Spack allows you to specify system installs of packages using a packages.yaml file.

Here is an example specifying system CUDA on MacOS:

# CUDA standard MacOS install
  cuda:
    paths:
      cuda@9.0: /Developer/NVIDIA/CUDA-9.0
  buildable: False

Here is an example of specifying system MPI and CUDA on an LLNL Chaos 5 machine:

# LLNL toss3 CUDA
  cuda:
    modules:
       cuda@9.1: cuda/9.1.85
    buildable: False
# LLNL toss3 mvapich2
  mvapich2:
    paths:
      mvapich2@2.2%gcc@4.9.3:  /usr/tce/packages/mvapich2/mvapich2-2.2-gcc-4.9.3
      mvapich2@2.2%intel@17.0.0: /usr/tce/packages/mvapich2/mvapich2-2.2-intel-17.0.0
      mvapich2@2.2%clang@4.0.0: /usr/tce/packages/mvapich2/mvapich2-2.2-clang-4.0.0
    buildable: False

Settings for LLNL TOSS 3 Systems:

• compilers.yaml
• packages.yaml

Using Ascent in Another Project

Under src/examples there are examples demonstrating how to use Ascent in a CMake-based build system (using-with-cmake) and via a Makefile (using-with-make). Under src/examples/proxies you can find example integrations using ascent in the Lulesh, Kripke, and Cloverleaf3D proxy-applications. In src/examples/synthetic/noise you can find an example integration using our synthetic smooth noise application.

Building Ascent in a Docker Container

Under src/examples/docker/master/ubuntu there is an example Dockerfile which can be used to create an ubuntu-based docker image with a build of the Ascent github master branch. There is also a script that demonstrates how to build a Docker image from the Dockerfile (example_build.sh) and a script that runs this image in a Docker container (example_run.sh). The Ascent repo is cloned into the image’s file system at /ascent, the build directory is /ascent/build-debug, and the install directory is /ascent/install-debug.

Building Ascent Dependencies Manually

In some environments, a spack build of Ascents dependencies can fail or a user may prefer to build the dependencies manually. This section describes how to build Ascents components. When building Ascents dependencies, it is highly recommended to fill out a host config file like the one located in /host-configs/boilerplate.cmake. This is the best way to avoid problems that can easily arise from mixing c++ standard libraries conflicts, MPI library conflicts, and fortran module conflicts, all of which are difficult to spot. Use the same CMake host-config file for each of Ascent’s dependencies, and while this may bring in unused cmake variables and clutter the ccmake curses interface, it will help avoid problems. In the host config, you can specify options such as ENABLE_PYTHON=OFF, ENABLE_FORTRAN=OFF, and ENABLE_MPI=ON that will be respected by both conduit and ascent.

HDF5 (Optional)

The HDF5 source tarball on the HDF5 group’s website. While the source contains both an autotools configure and CMake build system, use the CMake build system with your host config file. Once you have built and installed HDF5 into a local directory, add the location of that directory to the declaration of the HDF5_DIR in the host config file.

curl https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8/hdf5-1.8.16/src/hdf5-1.8.16.tar.gz > hdf5.tar.gz
tar -xzf hdf5.tar.gz
cd hdf5-1.8.16/
mkdir build
mkdir install
cd build
cmake -C path_to_host_config/myhost_config.cmake . \
  -DCMAKE_INSTALL_PREFIX=path_to_install -DCMAKE_BUILD_TYPE=Release
make install

In the host config, add set(HDF5_DIR "/path/to/hdf5_install" CACHE PATH "").

Conduit

The version of conduit we use is the master branch. If the HDF5_DIR is specified in the host config, then conduit will build the relay io library. Likewise, if the config file has the entry ENABLE_MPI=ON, then conduit will build parallel versions of the libraries. Once you have installed conduit, add the path to the install directory to your host config file in the cmake variable CONDUIT_DIR.

git clone --recursive https://github.com/LLNL/conduit.git
cd conduit
mkdir build
mkdir install
cd build
cmake -C path_to_host_config/myhost_config.cmake ../src \
  -DCMAKE_INSTALL_PREFIX=path_to_install -DCMAKE_BUILD_TYPE=Release
make install

In the host config, add set(CONDUIT_DIR "/path/to/conduit_install" CACHE PATH "").

VTK-m (Optional but recommended)

We currently use the master branch of vtkm and checkout a specific commit for stability. This is the current commit we build and test against:

vtkm branch='master' commit='a4dfe50cd50b6827491ac6e760a6a60940d8ba17'

We recommend VTK-m since VTK-m and VTK-h provide the majority of Ascent’s visualization and analysis functionality. The code below is minimal, and will only configure the serial device adapter. For instructions on building with TBB and CUDA, please consult the VTK-m repository. In Ascent, we require non-default configure options, so pay close attention to the extra cmake configure options.

git clone https://gitlab.kitware.com/vtk/vtk-m.git
cd vtk-m
git checkout commit_hash_listed_above
mkdir build
mkdir install
cmake -C path_to_host_config/myhost_config.cmake ../ -DCMAKE_INSTALL_PREFIX=path_to_install \
  -DCMAKE_BUILD_TYPE=Release -DVTKm_USE_64BIT_IDS=OFF -DVTKm_USE_DOUBLE_PRECISION=ON
make install

In the host config, add set(VTKM_DIR "/path/to/vtkm_install" CACHE PATH "").

VTK-h (Optional but recommended)

We recommend VTK-h since VTK-m and VTK-h provide the majority of Ascent’s visualization and analysis functionality. We currently use the develop branch of vtkm and checkout a specific commit for stability. This is the current commit we build and test against:

vtkh branch='develop' commit='b8504989173666e009d9ceb37a690b8284e42146'

git clone https://github.com/Alpine-DAV/vtk-h.git
cd vtk-h
git checkout commit_hash_listed_above
mkdir build
mkdir install
cd build
cmake -C path_to_host_config/myhost_config.cmake ../src -DCMAKE_INSTALL_PREFIX=path_to_install
make install

In the host config, add set(VTKH_DIR "/path/to/vtkh_install" CACHE PATH "").

Ascent

Now that we have all the dependencies built and a host config file for our environment, we can now build Ascent.

git clone --recursive https://github.com/Alpine-DAV/ascent.git
cd ascent
mkdir build
mkdir install
cd build
cmake -C path_to_host_config/myhost_config.cmake ../src -DCMAKE_INSTALL_PREFIX=path_to_install \
  -DCMAKE_BUILD_TYPE=Release
make install

To run the unit tests to make sure everything works, do make test. If you install these dependencies in a public place in your environment, we encourage you to make you host config publicly available by submitting a pull request to the Ascent repo. This will allow others to easily build on that system by only following the Ascent build instructions.

Asking Ascent how its configured

Once built, Ascent has a number of unit tests. t_ascent_smoke, located in the tests/ascent directory will print Ascent’s build configuration:

{
        "version": "0.4.0",
        "compilers":
        {
                "cpp": "/usr/tce/packages/gcc/gcc-4.9.3/bin/g++",
                "fortran": "/usr/tce/packages/gcc/gcc-4.9.3/bin/gfortran"
        },
        "platform": "linux",
        "system": "Linux-3.10.0-862.6.3.1chaos.ch6.x86_64",
        "install_prefix": "/usr/local",
        "mpi": "disabled",
        "runtimes":
        {
                "ascent":
                {
                        "status": "enabled",
                        "vtkm":
                        {
                                "status": "enabled",
                                "backends":
                                {
                                        "serial": "enabled",
                                        "openmp": "enabled",
                                        "cuda": "disabled"
                                }
                        }
                },
                "flow":
                {
                        "status": "enabled"
                }
        },
        "default_runtime": "ascent"
}

In this case, the non-MPI version of Ascent was used, so MPI reportsa as disabled.