remote execution implementation

cuopt uses embedded grpc client to solve problems on a remote server

Author: tmckayus

GRPC_ARCHITECTURE.md

@@ -15,11 +15,12 @@ REPODIR=$(cd "$(dirname "$0")"; pwd)
 LIBCUOPT_BUILD_DIR=${LIBCUOPT_BUILD_DIR:=${REPODIR}/cpp/build}
 LIBMPS_PARSER_BUILD_DIR=${LIBMPS_PARSER_BUILD_DIR:=${REPODIR}/cpp/libmps_parser/build}
 
-VALIDARGS="clean libcuopt libmps_parser cuopt_mps_parser cuopt cuopt_server cuopt_sh_client docs deb -a -b -g -fsanitize -tsan -msan -v -l= --verbose-pdlp --build-lp-only  --no-fetch-rapids --skip-c-python-adapters --skip-tests-build --skip-routing-build --skip-fatbin-write --host-lineinfo [--cmake-args=\\\"<args>\\\"] [--cache-tool=<tool>] -n --allgpuarch --ci-only-arch --show_depr_warn -h --help"
+VALIDARGS="clean libcuopt cuopt_grpc_server libmps_parser cuopt_mps_parser cuopt cuopt_server cuopt_sh_client docs deb -a -b -g -fsanitize -tsan -msan -v -l= --verbose-pdlp --build-lp-only  --no-fetch-rapids --skip-c-python-adapters --skip-tests-build --skip-routing-build --skip-fatbin-write --host-lineinfo [--cmake-args=\\\"<args>\\\"] [--cache-tool=<tool>] -n --allgpuarch --ci-only-arch --show_depr_warn -h --help"
 HELP="$0 [<target> ...] [<flag> ...]
  where <target> is:
    clean            - remove all existing build artifacts and configuration (start over)
    libcuopt         - build the cuopt C++ code
+   cuopt_grpc_server - build only the gRPC server binary (configures + builds libcuopt as needed)
    libmps_parser    - build the libmps_parser C++ code
    cuopt_mps_parser - build the cuopt_mps_parser python package
    cuopt            - build the cuopt Python package
@@ -358,8 +359,8 @@ if buildAll || hasArg libmps_parser; then
 fi
 
 ################################################################################
-# Configure, build, and install libcuopt
-if buildAll || hasArg libcuopt; then
+# Configure and build libcuopt (and optionally just the gRPC server)
+if buildAll || hasArg libcuopt || hasArg cuopt_grpc_server; then
     mkdir -p "${LIBCUOPT_BUILD_DIR}"
     cd "${LIBCUOPT_BUILD_DIR}"
     cmake -DDEFINE_ASSERT=${DEFINE_ASSERT} \
@@ -386,7 +387,10 @@ if buildAll || hasArg libcuopt; then
           "${EXTRA_CMAKE_ARGS[@]}" \
           "${REPODIR}"/cpp
     JFLAG="${PARALLEL_LEVEL:+-j${PARALLEL_LEVEL}}"
-    if hasArg -n; then
+    if hasArg cuopt_grpc_server && ! hasArg libcuopt && ! buildAll; then
+        # Build only the gRPC server (ninja resolves libcuopt as a dependency)
+        cmake --build "${LIBCUOPT_BUILD_DIR}" --target cuopt_grpc_server ${VERBOSE_FLAG} ${JFLAG}
+    elif hasArg -n; then
         # Manual make invocation to start its jobserver
         make ${JFLAG} -C "${REPODIR}/cpp" LIBCUOPT_BUILD_DIR="${LIBCUOPT_BUILD_DIR}" VERBOSE_FLAG="${VERBOSE_FLAG}" PARALLEL_LEVEL="${PARALLEL_LEVEL}" ninja-build
     else

SERVER_ARCHITECTURE.md

@@ -76,6 +76,9 @@ cache:
       - tbb-devel
       - zlib
       - bzip2
+      - grpc-cpp
+      - libprotobuf
+      - libuuid
     host:
       - cpp-argparse
       - cuda-version =${{ cuda_version }}
@@ -90,6 +93,8 @@ cache:
       - tbb-devel
       - zlib
       - bzip2
+      - grpc-cpp
+      - libprotobuf
 
 outputs:
   - package:
@@ -164,13 +169,17 @@ outputs:
         - libcublas
         - libcudss-dev >=0.7
         - libcusparse-dev
+        - grpc-cpp
+        - libprotobuf
       run:
         - ${{ pin_compatible("cuda-version", upper_bound="x", lower_bound="x") }}
         - ${{ pin_subpackage("libmps-parser", exact=True) }}
         - libboost-devel
         - librmm =${{ minor_version }}
         - cuda-nvrtc
         - libcudss
+        - grpc-cpp
+        - libprotobuf
       ignore_run_exports:
         by_name:
           - cuda-nvtx
@@ -212,6 +221,8 @@ outputs:
         - libcublas
         - libcudss-dev >=0.7
         - libcusparse-dev
+        - grpc-cpp
+        - libprotobuf
       run:
         - ${{ pin_subpackage("libcuopt", exact=True) }}
         - ${{ pin_subpackage("libmps-parser", exact=True) }}

build.sh

@@ -255,6 +255,92 @@ create_logger_macros(CUOPT "cuopt::default_logger()" include/cuopt)
 
 find_package(CUDSS REQUIRED)
 
+# ##################################################################################################
+# - gRPC and Protobuf setup (REQUIRED) ------------------------------------------------------------
+
+# gRPC is required for this branch - it provides remote execution features
+# gRPC can come from either:
+# - an installed CMake package (gRPCConfig.cmake), or
+# - an in-tree build (e.g. python/libcuopt uses FetchContent(grpc), which defines gRPC::grpc++).
+if(NOT TARGET gRPC::grpc++)
+  find_package(gRPC CONFIG REQUIRED)
+endif()
+
+# Find Protobuf (should come with gRPC, but verify)
+if(NOT TARGET protobuf::libprotobuf)
+  find_package(protobuf CONFIG REQUIRED)
+endif()
+
+set(CUOPT_ENABLE_GRPC ON)
+add_compile_definitions(CUOPT_ENABLE_GRPC)
+message(STATUS "gRPC enabled (target gRPC::grpc++ is available)")
+
+# Find protoc compiler (provided by config package or target)
+if(TARGET protobuf::protoc)
+  get_target_property(_PROTOBUF_PROTOC protobuf::protoc IMPORTED_LOCATION_RELEASE)
+  if(NOT _PROTOBUF_PROTOC)
+    get_target_property(_PROTOBUF_PROTOC protobuf::protoc IMPORTED_LOCATION)
+  endif()
+else()
+  find_package(protobuf CONFIG REQUIRED)
+  get_target_property(_PROTOBUF_PROTOC protobuf::protoc IMPORTED_LOCATION_RELEASE)
+  if(NOT _PROTOBUF_PROTOC)
+    get_target_property(_PROTOBUF_PROTOC protobuf::protoc IMPORTED_LOCATION)
+  endif()
+endif()
+
+if(NOT _PROTOBUF_PROTOC)
+  message(FATAL_ERROR "protoc not found (Protobuf_PROTOC_EXECUTABLE is empty)")
+endif()
+
+# Find grpc_cpp_plugin
+if(TARGET grpc_cpp_plugin)
+  set(_GRPC_CPP_PLUGIN_EXECUTABLE "$<TARGET_FILE:grpc_cpp_plugin>")
+else()
+  find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
+  if(NOT _GRPC_CPP_PLUGIN_EXECUTABLE)
+    message(FATAL_ERROR "grpc_cpp_plugin not found")
+  endif()
+endif()
+
+# Generate C++ code from cuopt_remote.proto (base message definitions)
+set(PROTO_FILE "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc/cuopt_remote.proto")
+set(PROTO_SRCS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote.pb.cc")
+set(PROTO_HDRS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote.pb.h")
+
+add_custom_command(
+  OUTPUT "${PROTO_SRCS}" "${PROTO_HDRS}"
+  COMMAND ${_PROTOBUF_PROTOC}
+  ARGS --cpp_out ${CMAKE_CURRENT_BINARY_DIR}
+       --proto_path ${CMAKE_CURRENT_SOURCE_DIR}/src/grpc
+       ${PROTO_FILE}
+  DEPENDS ${PROTO_FILE}
+  COMMENT "Generating C++ code from cuopt_remote.proto"
+  VERBATIM
+)
+
+# Generate gRPC service code from cuopt_remote_service.proto
+set(GRPC_PROTO_FILE "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc/cuopt_remote_service.proto")
+set(GRPC_PROTO_SRCS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote_service.pb.cc")
+set(GRPC_PROTO_HDRS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote_service.pb.h")
+set(GRPC_SERVICE_SRCS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote_service.grpc.pb.cc")
+set(GRPC_SERVICE_HDRS "${CMAKE_CURRENT_BINARY_DIR}/cuopt_remote_service.grpc.pb.h")
+
+add_custom_command(
+  OUTPUT "${GRPC_PROTO_SRCS}" "${GRPC_PROTO_HDRS}" "${GRPC_SERVICE_SRCS}" "${GRPC_SERVICE_HDRS}"
+  COMMAND ${_PROTOBUF_PROTOC}
+  ARGS --cpp_out ${CMAKE_CURRENT_BINARY_DIR}
+       --grpc_out ${CMAKE_CURRENT_BINARY_DIR}
+       --plugin=protoc-gen-grpc=${_GRPC_CPP_PLUGIN_EXECUTABLE}
+       --proto_path ${CMAKE_CURRENT_SOURCE_DIR}/src/grpc
+       ${GRPC_PROTO_FILE}
+  DEPENDS ${GRPC_PROTO_FILE} ${PROTO_FILE}
+  COMMENT "Generating gRPC C++ code from cuopt_remote_service.proto"
+  VERBATIM
+)
+
+message(STATUS "gRPC protobuf code generation configured")
+
 if(BUILD_TESTS)
   include(cmake/thirdparty/get_gtest.cmake)
 endif()
@@ -264,6 +350,20 @@ add_subdirectory(src)
 if (HOST_LINEINFO)
   set_source_files_properties(${CUOPT_SRC_FILES} DIRECTORY ${CMAKE_SOURCE_DIR} PROPERTIES COMPILE_OPTIONS "-g1")
 endif()
+
+# Add gRPC mapper files and generated protobuf sources
+list(APPEND CUOPT_SRC_FILES
+  ${PROTO_SRCS}
+  ${GRPC_PROTO_SRCS}
+  ${GRPC_SERVICE_SRCS}
+  src/grpc/grpc_problem_mapper.cu
+  src/grpc/grpc_solution_mapper.cu
+  src/grpc/grpc_settings_mapper.cu
+  src/grpc/grpc_service_mapper.cu
+  src/grpc/client/grpc_client.cu
+  src/grpc/client/solve_remote.cu
+)
+
 add_library(cuopt SHARED
   ${CUOPT_SRC_FILES}
 )
@@ -315,6 +415,9 @@ target_include_directories(cuopt
   PRIVATE
   "${CMAKE_CURRENT_SOURCE_DIR}/../thirdparty"
   "${CMAKE_CURRENT_SOURCE_DIR}/src"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc/client"
+  "${CMAKE_CURRENT_BINARY_DIR}"
   "${CUDSS_INCLUDE}"
   PUBLIC
   "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
@@ -384,6 +487,8 @@ target_link_libraries(cuopt
   ${CUDSS_LIB_FILE}
   PRIVATE
   ${CUOPT_PRIVATE_CUDA_LIBS}
+  protobuf::libprotobuf
+  gRPC::grpc++
   )
 
 
@@ -606,6 +711,109 @@ if(BUILD_LP_BENCHMARKS)
   endif()
 endif()
 
+# ##################################################################################################
+# - cuopt_grpc_server - gRPC-based remote server --------------------------------------------------
+
+add_executable(cuopt_grpc_server
+  src/grpc/server/grpc_server_main.cpp
+  src/grpc/server/grpc_worker.cpp
+  src/grpc/server/grpc_worker_infra.cpp
+  src/grpc/server/grpc_server_threads.cpp
+  src/grpc/server/grpc_job_management.cpp
+  src/grpc/server/grpc_service_impl.cpp
+)
+
+set_target_properties(cuopt_grpc_server
+  PROPERTIES
+  CXX_STANDARD 20
+  CXX_STANDARD_REQUIRED ON
+  CXX_SCAN_FOR_MODULES OFF
+)
+
+target_compile_options(cuopt_grpc_server
+  PRIVATE "$<$<COMPILE_LANGUAGE:CXX>:${CUOPT_CXX_FLAGS}>"
+)
+
+target_include_directories(cuopt_grpc_server
+  PRIVATE
+  "${CMAKE_CURRENT_SOURCE_DIR}/src"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc/server"
+  "${CMAKE_CURRENT_SOURCE_DIR}/include"
+  "${CMAKE_CURRENT_SOURCE_DIR}/libmps_parser/include"
+  "${CMAKE_CURRENT_BINARY_DIR}"
+  PUBLIC
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>"
+)
+
+find_library(UUID_LIBRARY uuid REQUIRED)
+
+target_link_libraries(cuopt_grpc_server
+  PUBLIC
+  cuopt
+  OpenMP::OpenMP_CXX
+  PRIVATE
+  protobuf::libprotobuf
+  gRPC::grpc++
+  ${UUID_LIBRARY}
+)
+
+# Use RUNPATH when building locally
+target_link_options(cuopt_grpc_server PRIVATE -Wl,--enable-new-dtags)
+set_property(TARGET cuopt_grpc_server PROPERTY INSTALL_RPATH "$ORIGIN/../${lib_dir}")
+
+# Install the grpc server executable
+install(TARGETS cuopt_grpc_server
+  COMPONENT runtime
+  RUNTIME DESTINATION ${_BIN_DEST}
+)
+
+message(STATUS "Building cuopt_grpc_server (gRPC-based remote solve server)")
+
+# ##################################################################################################
+# - test_grpc_client - Simple test client for cuopt_grpc_server -----------------------------------
+
+add_executable(test_grpc_client src/grpc/client/test_grpc_client.cpp)
+
+set_target_properties(test_grpc_client
+  PROPERTIES
+  CXX_STANDARD 20
+  CXX_STANDARD_REQUIRED ON
+  CXX_SCAN_FOR_MODULES OFF
+)
+
+target_compile_options(test_grpc_client
+  PRIVATE "$<$<COMPILE_LANGUAGE:CXX>:${CUOPT_CXX_FLAGS}>"
+)
+
+target_include_directories(test_grpc_client
+  PRIVATE
+  "${CMAKE_CURRENT_SOURCE_DIR}/src"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/grpc/client"
+  "${CMAKE_CURRENT_SOURCE_DIR}/include"
+  "${CMAKE_CURRENT_SOURCE_DIR}/libmps_parser/include"
+  "${CMAKE_CURRENT_BINARY_DIR}"
+  PUBLIC
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>"
+)
+
+target_link_libraries(test_grpc_client
+  PUBLIC
+  cuopt
+  PRIVATE
+  protobuf::libprotobuf
+  gRPC::grpc++
+)
+
+# Use RUNPATH when building locally
+target_link_options(test_grpc_client PRIVATE -Wl,--enable-new-dtags)
+set_property(TARGET test_grpc_client PROPERTY INSTALL_RPATH "$ORIGIN/../${lib_dir}")
+
+message(STATUS "Building test_grpc_client (simple gRPC client for testing)")
+
 
 # ##################################################################################################
 # - CPack has to be the last item in the cmake file-------------------------------------------------