Fix issue with mlflow.start_run(run_uuid=<deleted_run>) (mlflow#579)

* init

* fix lint

mlflow/tracking/fluent.py

@@ -12,7 +12,8 @@
 import sys
 import time
 
-from mlflow.entities import Experiment, Run, SourceType
+from mlflow.entities import Experiment, Run, SourceType, RunInfo
+from mlflow.exceptions import MlflowException
 from mlflow.tracking.client import MlflowClient
 from mlflow.utils import env
 from mlflow.utils.databricks_utils import is_in_databricks_notebook, get_notebook_id, \
@@ -102,6 +103,9 @@ def start_run(run_uuid=None, experiment_id=None, source_name=None, source_versio
     if existing_run_uuid:
         _validate_run_id(existing_run_uuid)
         active_run_obj = MlflowClient().get_run(existing_run_uuid)
+        if active_run_obj.info.lifecycle_stage == RunInfo.DELETED_LIFECYCLE:
+            raise MlflowException("Cannot start run with ID {} because it is in the "
+                                  "deleted state.".format(existing_run_uuid))
     else:
         if len(_active_run_stack) > 0:
             parent_run_id = _active_run_stack[-1].info.run_uuid

tests/tracking/test_tracking.py

@@ -8,6 +8,7 @@
 import mlflow
 from mlflow import tracking
 from mlflow.entities import RunStatus
+from mlflow.exceptions import MlflowException
 from mlflow.tracking.fluent import start_run, end_run
 from mlflow.utils.mlflow_tags import MLFLOW_PARENT_RUN_ID
 from tests.projects.utils import tracking_uri_mock
@@ -193,14 +194,14 @@ def test_uri_types():
 
 
 def test_with_startrun():
-    runId = None
+    run_id = None
     import time
     t0 = int(time.time() * 1000)
     with mlflow.start_run() as active_run:
         assert mlflow.active_run() == active_run
-        runId = active_run.info.run_uuid
+        run_id = active_run.info.run_uuid
     t1 = int(time.time() * 1000)
-    run_info = mlflow.tracking._get_store().get_run(runId).info
+    run_info = mlflow.tracking._get_store().get_run(run_id).info
     assert run_info.status == RunStatus.from_string("FINISHED")
     assert t0 <= run_info.end_time and run_info.end_time <= t1
     assert mlflow.active_run() is None
@@ -224,3 +225,14 @@ def verify_has_parent_id_tag(child_id, expected_parent_id):
     mlflow.end_run()
     mlflow.end_run()
     assert mlflow.active_run() is None
+
+
+def test_start_deleted_run():
+    run_id = None
+    with mlflow.start_run() as active_run:
+        run_id = active_run.info.run_uuid
+    tracking.MlflowClient().delete_run(run_id)
+    with pytest.raises(MlflowException, matches='because it is in the deleted state.'):
+        with mlflow.start_run(run_uuid=run_id):
+            pass
+    assert mlflow.active_run() is None