Fix: DAGs are not marked as stale if the dags folder change

airflow/dag_processing/manager.py

@@ -526,14 +526,20 @@ def deactivate_stale_dags(
         dags_parsed = session.execute(query)
 
         for dag in dags_parsed:
+            # When the DAG processor runs as part of the scheduler, and the user changes the DAGs folder,
+            # DAGs from the previous DAGs folder will be marked as stale. Note that this change has no impact
+            # on standalone DAG processors.
+            dag_not_in_current_dag_folder = os.path.commonpath([dag.fileloc, dag_directory]) != dag_directory
             # The largest valid difference between a DagFileStat's last_finished_time and a DAG's
             # last_parsed_time is the processor_timeout. Longer than that indicates that the DAG is
             # no longer present in the file. We have a stale_dag_threshold configured to prevent a
             # significant delay in deactivation of stale dags when a large timeout is configured
-            if (
+            dag_removed_from_dag_folder_or_file = (
                 dag.fileloc in last_parsed
                 and (dag.last_parsed_time + timedelta(seconds=stale_dag_threshold)) < last_parsed[dag.fileloc]
-            ):
+            )
+
+            if dag_not_in_current_dag_folder or dag_removed_from_dag_folder_or_file:
                 cls.logger().info("DAG %s is missing and will be deactivated.", dag.dag_id)
                 to_deactivate.add(dag.dag_id)
 

tests/dag_processing/test_job_runner.py

@@ -26,6 +26,7 @@
 import random
 import socket
 import sys
+import tempfile
 import textwrap
 import threading
 import time
@@ -638,7 +639,7 @@ def test_scan_stale_dags(self):
         manager = DagProcessorJobRunner(
             job=Job(),
             processor=DagFileProcessorManager(
-                dag_directory="directory",
+                dag_directory=str(TEST_DAG_FOLDER),
                 max_runs=1,
                 processor_timeout=timedelta(minutes=10),
                 signal_conn=MagicMock(),
@@ -712,11 +713,11 @@ def test_scan_stale_dags_standalone_mode(self):
         """
         Ensure only dags from current dag_directory are updated
         """
-        dag_directory = "directory"
+        dag_directory = str(TEST_DAG_FOLDER)
         manager = DagProcessorJobRunner(
             job=Job(),
             processor=DagFileProcessorManager(
-                dag_directory=dag_directory,
+                dag_directory=TEST_DAG_FOLDER,
                 max_runs=1,
                 processor_timeout=timedelta(minutes=10),
                 signal_conn=MagicMock(),
@@ -740,7 +741,7 @@ def test_scan_stale_dags_standalone_mode(self):
             # Add stale DAG to the DB
             other_dag = other_dagbag.get_dag("test_start_date_scheduling")
             other_dag.last_parsed_time = timezone.utcnow()
-            other_dag.sync_to_db(processor_subdir="other")
+            other_dag.sync_to_db(processor_subdir="/other")
 
             # Add DAG to the file_parsing_stats
             stat = DagFileStat(
@@ -762,6 +763,68 @@ def test_scan_stale_dags_standalone_mode(self):
             active_dag_count = session.query(func.count(DagModel.dag_id)).filter(DagModel.is_active).scalar()
             assert active_dag_count == 1
 
+    def test_scan_stale_dags_when_dag_folder_change(self):
+        """
+        Ensure dags from old dag_folder is marked as stale when dag processor
+         is running as part of scheduler.
+        """
+
+        def get_dag_string(filename) -> str:
+            return open(TEST_DAG_FOLDER / filename).read()
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            old_dag_home = tempfile.mkdtemp(dir=tmpdir)
+            old_dag_file = tempfile.NamedTemporaryFile(dir=old_dag_home, suffix=".py")
+            old_dag_file.write(get_dag_string("test_example_bash_operator.py").encode())
+            old_dag_file.flush()
+            new_dag_home = tempfile.mkdtemp(dir=tmpdir)
+            new_dag_file = tempfile.NamedTemporaryFile(dir=new_dag_home, suffix=".py")
+            new_dag_file.write(get_dag_string("test_scheduler_dags.py").encode())
+            new_dag_file.flush()
+
+            manager = DagProcessorJobRunner(
+                job=Job(),
+                processor=DagFileProcessorManager(
+                    dag_directory=new_dag_home,
+                    max_runs=1,
+                    processor_timeout=timedelta(minutes=10),
+                    signal_conn=MagicMock(),
+                    dag_ids=[],
+                    pickle_dags=False,
+                    async_mode=True,
+                ),
+            )
+
+            dagbag = DagBag(old_dag_file.name, read_dags_from_db=False)
+            other_dagbag = DagBag(new_dag_file.name, read_dags_from_db=False)
+
+            with create_session() as session:
+                # Add DAG from old dah home to the DB
+                dag = dagbag.get_dag("test_example_bash_operator")
+                dag.fileloc = old_dag_file.name
+                dag.last_parsed_time = timezone.utcnow()
+                dag.sync_to_db(processor_subdir=old_dag_home)
+
+                # Add DAG from new DAG home to the DB
+                other_dag = other_dagbag.get_dag("test_start_date_scheduling")
+                other_dag.fileloc = new_dag_file.name
+                other_dag.last_parsed_time = timezone.utcnow()
+                other_dag.sync_to_db(processor_subdir=new_dag_home)
+
+                manager.processor._file_paths = [new_dag_file]
+
+                active_dag_count = (
+                    session.query(func.count(DagModel.dag_id)).filter(DagModel.is_active).scalar()
+                )
+                assert active_dag_count == 2
+
+                manager.processor._scan_stale_dags()
+
+                active_dag_count = (
+                    session.query(func.count(DagModel.dag_id)).filter(DagModel.is_active).scalar()
+                )
+                assert active_dag_count == 1
+
     @mock.patch(
         "airflow.dag_processing.processor.DagFileProcessorProcess.waitable_handle", new_callable=PropertyMock
     )

tests/jobs/test_scheduler_job.py

@@ -3568,6 +3568,7 @@ def test_retry_still_in_executor(self, dag_maker):
                 dag_id="test_retry_still_in_executor",
                 schedule="@once",
                 session=session,
+                fileloc=os.devnull + "/test_retry_still_in_executor.py",
             ):
                 dag_task1 = BashOperator(
                     task_id="test_retry_handling_op",