New `MLFLOW_KEEP_RUN_ACTIVE` flag for enhanced MLflow run management (#8808)

Co-authored-by: UltralyticsAssistant <web@ultralytics.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

.gitignore

@@ -50,6 +50,7 @@ coverage.xml
 *.py,cover
 .hypothesis/
 .pytest_cache/
+mlruns/
 
 # Translations
 *.mo

tests/test_integrations.py

@@ -29,6 +29,34 @@ def test_mlflow():
     SETTINGS["mlflow"] = True
     YOLO("yolov8n-cls.yaml").train(data="imagenet10", imgsz=32, epochs=3, plots=False, device="cpu")
 
+@pytest.mark.skipif(not check_requirements('mlflow', install=False), reason='mlflow not installed')
+def test_mlflow_keep_run_active():
+    import os
+    import mlflow
+    """Test training with MLflow tracking enabled."""
+    SETTINGS['mlflow'] = True
+    run_name = 'Test Run'
+    os.environ['MLFLOW_RUN'] = run_name
+
+    # Test with MLFLOW_KEEP_RUN_ACTIVE=True
+    os.environ['MLFLOW_KEEP_RUN_ACTIVE'] = 'True'
+    YOLO('yolov8n-cls.yaml').train(data='imagenet10', imgsz=32, epochs=1, plots=False, device='cpu')
+    status = mlflow.active_run().info.status
+    assert status == 'RUNNING', "MLflow run should be active when MLFLOW_KEEP_RUN_ACTIVE=True"
+
+    run_id = mlflow.active_run().info.run_id
+
+    # Test with MLFLOW_KEEP_RUN_ACTIVE=False
+    os.environ['MLFLOW_KEEP_RUN_ACTIVE'] = 'False'
+    YOLO('yolov8n-cls.yaml').train(data='imagenet10', imgsz=32, epochs=1, plots=False, device='cpu')
+    status = mlflow.get_run(run_id=run_id).info.status
+    assert status == 'FINISHED', "MLflow run should be ended when MLFLOW_KEEP_RUN_ACTIVE=False"
+
+    # Test with MLFLOW_KEEP_RUN_ACTIVE not set
+    os.environ.pop('MLFLOW_KEEP_RUN_ACTIVE', None)
+    YOLO('yolov8n-cls.yaml').train(data='imagenet10', imgsz=32, epochs=1, plots=False, device='cpu')
+    status = mlflow.get_run(run_id=run_id).info.status
+    assert status == 'FINISHED', "MLflow run should be ended by default when MLFLOW_KEEP_RUN_ACTIVE is not set"
 
 @pytest.mark.skipif(not check_requirements("tritonclient", install=False), reason="tritonclient[all] not installed")
 def test_triton():

ultralytics/utils/callbacks/mlflow.py

@@ -58,6 +58,7 @@ def on_pretrain_routine_end(trainer):
         MLFLOW_TRACKING_URI: The URI for MLflow tracking. If not set, defaults to 'runs/mlflow'.
         MLFLOW_EXPERIMENT_NAME: The name of the MLflow experiment. If not set, defaults to trainer.args.project.
         MLFLOW_RUN: The name of the MLflow run. If not set, defaults to trainer.args.name.
+        MLFLOW_KEEP_RUN_ACTIVE: Boolean indicating whether to keep the MLflow run active after the end of the training phase.
     """
     global mlflow
 
@@ -107,8 +108,13 @@ def on_train_end(trainer):
         for f in trainer.save_dir.glob("*"):  # log all other files in save_dir
             if f.suffix in {".png", ".jpg", ".csv", ".pt", ".yaml"}:
                 mlflow.log_artifact(str(f))
+        keep_run_active = os.environ.get("MLFLOW_KEEP_RUN_ACTIVE", "False").lower() in ("true")
+        if keep_run_active:
+            LOGGER.info(f"{PREFIX}mlflow run still alive, remember to close it using mlflow.end_run()")
+        else:
+            mlflow.end_run()
+            LOGGER.debug(f"{PREFIX}mlflow run ended")
 
-        mlflow.end_run()
         LOGGER.info(
             f"{PREFIX}results logged to {mlflow.get_tracking_uri()}\n"
             f"{PREFIX}disable with 'yolo settings mlflow=False'"