Merge pull request #3606 from nzw0301/separate-mpi

Extract mpi tests from integration CI as independent CI

.github/workflows/tests-integration.yml

@@ -78,14 +78,3 @@ jobs:
           pytest -s tests/integration_tests \
             --ignore tests/integration_tests/test_pytorch_lightning.py
         fi
-
-    - name: Tests MPI
-      run: |
-        mpirun -n 2 -- pytest tests/integration_tests/test_chainermn.py
-
-        if [ ${{ matrix.python-version }} != 3.6 ]; then
-          mpirun -n 2 -- pytest tests/integration_tests/test_pytorch_distributed.py
-        fi
-
-      env:
-        OMP_NUM_THREADS: 1

.github/workflows/tests-mpi.yml

@@ -0,0 +1,69 @@
+name: Tests (MPI)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request: {}
+  schedule:
+    - cron: '0 23 * * SUN-THU'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref == 'refs/heads/master' && github.run_number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  tests-mpi:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Setup Python${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Setup cache
+      uses: actions/cache@v2
+      env:
+        cache-name: test-mpi
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-${{ matrix.python-version }}-${{ env.cache-name }}-${{ hashFiles('**/setup.py') }}-v1
+        restore-keys: |
+          ${{ runner.os }}-${{ matrix.python-version }}-${{ env.cache-name }}-${{ hashFiles('**/setup.py') }}
+
+    - name: Setup environment
+      run: |
+        sudo apt-get update
+        sudo apt-get -y install openmpi-bin libopenmpi-dev
+
+    - name: Install
+      run: |
+        python -m pip install --upgrade pip
+
+        # Install minimal dependencies and confirm that `import optuna` is successful.
+        pip install --progress-bar off .
+        python -c 'import optuna'
+        optuna --version
+
+        pip install --progress-bar off .[test]
+        pip install --progress-bar off .[optional]
+        pip install --progress-bar off .[integration] --extra-index-url https://download.pytorch.org/whl/cpu
+
+    - name: Tests
+      run: |
+        mpirun -n 2 -- pytest tests/integration_tests/test_chainermn.py
+
+        if [ ${{ matrix.python-version }} != 3.6 ]; then
+          mpirun -n 2 -- pytest tests/integration_tests/test_pytorch_distributed.py
+        fi
+
+      env:
+        OMP_NUM_THREADS: 1