Hermes

Hermes is a heterogeneous-aware, multi-tiered, dynamic, and distributed I/O buffering system that aims to significantly accelerate I/O performance. See the official site for more information. For design documents, architecture description, performance data, and individual component design, see the wiki.

Dependencies

• A C++ compiler that supports C++ 17.
• Thallium - RPC library for HPC. Use a version greater than 0.5 for RoCE support.
• GLOG - The Google logging library (v0.4.0). (If you install the ORTOOLS binary, GLOG is included).
• Google ORTOOLS for constraint optimization (tested with v7.7.7810).
  • Download the OR-Tools binary distribution for C++.
  • Setup ORTOOLS_DIR as a cmake environment variable.
• MPI (tested with MPICH 3.3.2 and OpenMPI 4.0.3).
• The Catch2 testing framework (only required if built with -DBUILD_TESTING=ON)

Building

CMake

Hermes makes use of the CMake build system and requires an out of source build.

cd /path/to/hermes
mkdir build
cd build
ccmake ..

Type 'c' to configure until there are no errors, then generate the makefile with 'g'. The default options should suffice for most use cases. In addition, we recommend the following options.

-DCMAKE_INSTALL_PREFIX=/installation/prefix
-DCMAKE_PREFIX_PATH=/path/to/dependencies
-DCMAKE_BUILD_RPATH=/path/to/dependencies/lib
-DCMAKE_INSTALL_RPATH=/path/to/dependencies/lib
-DCMAKE_BUILD_TYPE=Release
-DCMAKE_CXX_COMPILER=`which mpicxx`
-DBUILD_SHARED_LIBS=ON
-DORTOOLS_DIR=/path/to/ortools

After the makefile has been generated, you can type make -j 4 or cmake --build . -- -j 4. Add VERBOSE=1 to see detailed compiler output.

spack

# set location of current spack to SPACK_DIR or clone it.
SPACK_DIR=~/spack
git clone https://github.com/spack/spack ${SPACK_DIR}
# set location of hermes_file_staging
STAGE_DIR=~/hermes_stage
# no change from this point
MOCHI_REPO=${STAGE_DIR}/mochi
HERMES_REPO=${STAGE_DIR}/hermes
git clone https://github.com/mochi-hpc/mochi-spack-packages.git ${MOCHI_REPO}
git clone https://github.com/HDFGroup/hermes ${HERMES_REPO}
. ${SPACK_DIR}/share/spack/setup-env.sh
spack repo add ${MOCHI_REPO}
spack repo add ${HERMES_REPO}/ci/hermes
spack install hermes

Testing and Installation

After successfully building Hermes, it's a good idea to run the test suite via the command ctest .. This should be run from the build directory.

Finally, install the library with make install. You can find a complete example build script here.

Contributing

We follow the Google C++ Style Guide. You can run make lint to ensure that your code conforms to the style. This requires the cpplint Python module (pip install cpplint). Alternatively, you can let the CI build inform you of required style changes.