docs-archive/apache-airflow/2.4.0/_sources/_api/airflow/example_dags/example_external_task_marker_dag/index.rst.txt

:py:mod:`airflow.example_dags.example_external_task_marker_dag`
===============================================================

.. py:module:: airflow.example_dags.example_external_task_marker_dag

.. autoapi-nested-parse::

   Example DAG demonstrating setting up inter-DAG dependencies using ExternalTaskSensor and
   ExternalTaskMarker.

   In this example, child_task1 in example_external_task_marker_child depends on parent_task in
   example_external_task_marker_parent. When parent_task is cleared with 'Recursive' selected,
   the presence of ExternalTaskMarker tells Airflow to clear child_task1 and its downstream tasks.

   ExternalTaskSensor will keep poking for the status of remote ExternalTaskMarker task at a regular
   interval till one of the following will happen:

   ExternalTaskMarker reaches the states mentioned in the allowed_states list.
   In this case, ExternalTaskSensor will exit with a success status code

   ExternalTaskMarker reaches the states mentioned in the failed_states list
   In this case, ExternalTaskSensor will raise an AirflowException and user need to handle this
   with multiple downstream tasks

   ExternalTaskSensor times out. In this case, ExternalTaskSensor will raise AirflowSkipException
   or AirflowSensorTimeout exception



Module Contents
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.. py:data:: start_date
   

   

.. py:data:: parent_task
   

   

.. py:data:: child_task1