Externaltasksensor airflow 2. from airflow import DAG from airflow.

Externaltasksensor airflow 2 utils. The test_dag_son shouldn't have any schedule. Airflow ExternalTaskSensor with different scheduler interval. One of those datasets has already been updated by an Apache Airflow version: 2. TaskGroups, introduced in Airflow 2. There are two dags Parent and Child, parent has its own schedule, suppose '30 * * * * ', child '1 8-17 * * 1-5', child waits for parent Users who are familiar with building ETL pipelines using Apache Airflow often use the ExternalTaskSensor in order to establish a cross dependency between two dags. What happened. I. python_operator import PythonOperator from airflow. However, when a dag is triggered manually or by another dag, you cannot known for sure the the exact execution date class ExternalTaskSensor (BaseSensorOperator): """ Waits for a different DAG or a task in a different DAG to complete for a specific execution_date:param external_dag_id: The dag_id that contains the task you want to wait for:type external_dag_id: str:param external_task_id: The task_id that contains the task you want to wait for. 1 What happened If trying to wait for a DAG currently in a deferred state using the ExternalTaskSensor in deferrable mode, the sensor doesn't consider that the DAG is running and fails after 60 seconds. Airflow ExternalTaskSensor poking another dag all the time. Bases: To make a task in a DAG wait for another task in a different DAG for a specific execution_date, from airflow. Viewed 10k times 7 Colleagues, we need help. Still, it didn't trigger the DAG when upstream one got finished. In other words, if the latest successful DagRun of the daily DAG does not align with the execution date of our hourly DAG, the task I removed execution_delta and set the schedule_interval to 0 1 * * *. Airflow execute task in sequence without defining dependency. We've made extensive use of [ExternalTaskSensor][1] to the point where the quantity of cross-dag dependencies have become difficult to track. If you have an ExternalTaskSensor that uses external_task_group_id to wait on a TaskGroup, and if that TaskGroup contains any skipped tasks, the sensor will be stuck waiting forever despite the UI saying the state of the TaskGroup is successful. This sensor is useful if you want to implement cross-DAG dependencies in the same Airflow environment. 0, I think there is no need to use ExternalTaskSensor. Airflow ExternalTaskSensor execution timeout. 10. If ``None`` the sensor waits for the We use ExternalTaskSensor in a few places in our airflow deployment. Different task schedules The problem is probably related to executor, start_date's or poke_interval. 3. Parameters. Ideally the template should be expanded. ExternalTaskSensor To configure the sensor, we need the identifier of another DAG (we will wait until that DAG finishes). With execution_delta set, the ExternalTaskSensor will check for the task with execution date execution_date - execution_delta. sensors. Notifications You must be signed in to change notification settings; Fork 14. Let's do a little test with LocalExecutor. I am trying to create a DAG that depends on several other DAGs by that they shouldn't run simultaneously. ExternalTaskSensor (external_dag_id, external_task_id, allowed_states=None, execution_delta=None, execution_date_fn=None, check_existence=False, *args, **kwargs) [source] ¶. . This can be used to establish To establish cross-DAG dependencies using a sensor, the downstream DAG needs to include the ExternalTaskSensor, Hence, if you’re utilizing an Airflow version of 2. 0 has been released with many exciting improvements. Airflow: ExternalTaskSensor doesn't work as expected. An Airflow DAG can become very complex if we start including all dependencies in it, and furthermore, this strategy allows us to decouple the processes, for example, by teams of data engineers, by departments, or any other criteria. According to the docs, Airflow 2. Airflow setting conditional dependency. HttpSensor: Waits for an API to be available. The ExternalTaskSensor is set up with execution_delta=timedelta(minutes=30) My expected flow of the tasks would be: at first the extract dag is run. 10. Waits for a different DAG, task ExternalTaskSensor has a execution_date_fn Apache Airflow's ExternalTaskSensor is a powerful feature that allows one DAG to wait for a In this introductory piece, I hope to untangle some of the confusion surrounding the External Task Sensor and show how we can use it to enhance the reliability of our data pipelines — making sense of sensors! Why do we To address these cross-DAG dependencies, Airflow provides the ExternalTaskSensor, a built Airflow provides an out-of-the-box sensor called ExternalTaskSensor that we It allows users to access DAG waited with ExternalTaskSensor. They allow you to group tasks together in a visually appealing way without the execution overhead of SubDAGs. Unable to run Airflow Tasks due to execution date and start date. if the external task runs at 9/17 4 AM then the execution date is set to 9/16 10 PM (which is the previous I am trying to create dependency between multiple dags. It allows users to access DAG waited with ExternalTaskSensor or cleared by ExternalTaskMarker. external_task import ExternalTaskMarker, ExternalTaskSensor Apache Airflow version. That means if the DAG containing the TaskSensor triggered at 9/17 2 AM, the execution date of the sensor was set to 9/17 2 AM. The timeout is OK to be 90 seconds, as the test_dag_son is finishing within less than 30 seconds. session import provide_session class SmartExternalTaskSensor(ExternalTaskSensor): # Something a bit odd The Apache Airflow ExternalTaskSensor is a powerful and versatile tool for managing cross-DAG dependencies in your data pipelines. execution_date_fn=get_execution_date_of_dependent_dag('dag_a') Conclusion. now i want to run Dag_C which runs at 14:30 having 2 sensor Apache Airflow version. dates import days_ago start_date = days_ago(1) # run the day zero once, then start running incremental with DAG(dag_id="dayzero_dag", ExternalTaskSensor: Waits for an Airflow task to be completed. external_task_sensor. This sensor is I just tested your code with airflow from 2. import time from datetime import datetime, timedelta from airflow import DAG from airflow. In Airflow 1. 3, it didn't work with 2. We're proud to announce that Apache Airflow 2. This sensor functions correctly when the external DAG exists (normal operation By default the ExternalTaskSensor will monitor the external_dag_id with the same execution date that the sensor DAG. 3. First, estimate the usecase for the most recent run, as opposed to ExternalTaskSensor, which looks for a run at a specific logical time. apache / airflow Public. 0, sensors can be set to deferrable mode, which class ExternalTaskMarker (DummyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. sensors import external_task sensor = external_task. ExternalTaskSensorLink [source] By default the ExternalTaskSensor will wait for the external task to succeed, at which point it will also succeed. external_task import ExternalTaskSensor # Define task 1 def failed_states was added in Airflow 2. ; Solution: Ensure that the poke_interval is set correctly and that the sensor's mode is not set to class ExternalTaskSensor (BaseSensorOperator): """ Waits for a different DAG or a task in a different DAG to complete for a specific execution_date:param external_dag_id: The dag_id that contains the task you want to wait for:type external_dag_id: str:param external_task_id: The task_id that contains the task you want to wait for. Help me crack this one. Since we FAIL the DAG with External Task Sensor when executi In this case, ExternalTaskSensor will raise AirflowSkipException or AirflowSensorTimeout exception """ from __future__ import annotations import pendulum from airflow. The second approach involves a more customised solution. Operator link for ExternalTaskSensor. python import PythonOperator dag = DAG( 'test_first_dag', start_date=datetime(2024, 1, 1), schedule_interval=timedelta(days=1), class airflow. test_first_dag. e. 18 Environment: Linux Cloud provider or hardware configuration: AWS OS (e. 6. 1. 3 If "Other Airflow 2 version" selected, which one? No response What happened? The WorkflowTrigger used by ExternalTaskSensor should have a time limit set from timeout attribute instead of execution_timeout ai I'm new to Airflow. If given a task ID, it'll monitor the task state, otherwise it monitors DAG run state. With execution_delta you can set a time delta between the sensor dag and the external dag so it can look for the correct execution_date to monitor. import datetime from airflow. Hot Network Questions Airflow: ExternalTaskSensor doesn't work as expected. ExternalDagLink [source] ¶. BaseSensorOperator Waits for a different DAG or a class ExternalTaskSensor (BaseSensorOperator): """ Waits for a task to complete in a different DAG:param external_dag_id: The dag_id that contains the task you want to wait for:type external_dag_id: string:param external_task_id: The task_id that contains the task you want to wait for:type external_task_id: string:param allowed_states: list of allowed states, default is Define an ExternalTaskSensor in DAG_A that senses the completion of Task_B in DAG_B. By this I mean that some of our DAGs are not scheduled but externally triggered using the Airflow API. Looks like it probably has something to do with start date of both the DAGs but I am not able to figure it out yet. This can be done class ExternalTaskMarker (DummyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. ExternalTaskSensor¶ Use the ExternalTaskSensor to make tasks on a DAG wait for another Waits for a different DAG or a task in a different DAG to complete for a specific Operator link for ExternalTaskSensor and ExternalTaskMarker. For Airflow 2. However, TriggerDagRunOperator takes parent DAGs execution_date (logical_date) for execution and that just reruns same instance of triggered DAG instead of running new instance with new config. class airflow. I have DAG 1 running Daily and DAG 2 - Weekly. Extracting this info would allow us to from airflow. models import DAG from airflow. 0 to 2. Bases: airflow. state import State sensors_dag = DAG( "test_launch_sensors class ExternalTaskSensor (BaseSensorOperator): """ Waits for a different DAG or a task in a different DAG to complete for a specific execution_date:param external_dag_id: The dag_id that contains the task you want to wait for:type external_dag_id: str:param external_task_id: The task_id that contains the task you want to wait for. I tried to add soft_fail ExternalTaskSensor in Airflow UI and Re-direct button. Transitive dependencies are followed until the recursion_depth is reached. 1 I first installed Amazon provider: pip install apache-airflow-providers-amazon and then imported S3KeySensor: I plan to use TriggerDagRunOperator and ExternalTaskSensor . 4 Create an Airflow ExternalTaskSensor for a specific run of an external Task that runs multiple times in a class ExternalTaskSensor (BaseSensorOperator): """ Waits for a different DAG or a task in a different DAG to complete for a specific execution_date:param external_dag_id: The dag_id that contains the task you want to wait for:type external_dag_id: str:param external_task_id: The task_id that contains the task you want to wait for. Using TriggerDagRunOperator, you could create and schedule a DAG that acts as a controller, having two tasks responsible for triggering DAG_A and DAG_B. Airflow - Dynamic Tasks and Downstream Dependencies. I need to come up with a clean easy solution for DAG dependencies with different schedules. Airflow ExternalTaskSensor don't fail when External Task fails. The most notable place is at the start of our dbt running DAG. It allows users to access DAG waited with ExternalTaskSensor. If ``None`` (default Using 'ExternalTaskMarker' to Clear Dependent Tasks in Apache Airflow. the first DAG run will start on the 26th at 00:00, and the ExternalTaskSensor will check for a task with execution_date of 25th 00:00 - 24 hours = 24th 00:00. x, unfortunately, the ExternalTaskSensor operation only compares DAG run or task state against allowed_states; Apache Airflow's ExternalTaskSensor is a powerful feature that allows one DAG to wait for a task or a task group to complete in another DAG before proceeding. external_dag_id – The dag_id that contains the dependent task that class airflow. In this case, ExternalTaskSensor keeps running forever since it is poking to instance with execution_date as master DAGs execution_date (i. As such we would like a method of extracting all tasks that use this sensor as well as the parameters passed to these tasks such as external_dag_id and external_task_id. Different task schedules. Airflow ExternalTaskSensor manually triggered. external_task_sensor import ExternalTaskSensor import I get similar issues trying to use ExternalTaskSensor as a SmartSensor. Ask Question Asked 3 years, 9 months ago. This works great when both dags are run in a the same schedule or when you know exactly the timedelta between the two. 9k. ExternalTaskSensor( task_id='sensor', dag=dag, external_dag_id='DAG2 In this article we are going to tell you some ways to solve problems related to the complexity of data engineering itself. Yes, you heard it right. However the execution date of the external task was set to previous execution date (which is the default Lakitu behaviour) i. ; I ran the test_dag_father using schedule. 9. ExternalTaskSensor works by polling the state of DagRun / TaskInstance of the external DAG or task respectively (based on whether or not external_task_id is passed); Now since a single DAG can have multiple active DagRuns, the sensor must be told that which of these runs / instances it is supposed to sense; For that, it uses execution_date By default the ExternalTaskSensor will monitor the external_dag_id with the same execution date that the sensor DAG. 0 Kubernetes version (if you are using kubernetes) (use kubectl version): 1. If ``None`` (default Apache Airflow version Other Airflow 2 version (please specify below) What happened My DAG has a number of tasks, the first of which is an ExternalTaskSensor. Lets say Dag_A, Dab_B and and running every day at 14:15 and 14:30 respectively. To clear dependent tasks, you would need to clear the ExternalTaskMarker task. 2 ETL when using ExternalTaskSensor for DAG task dependency? Airflow externaltasksensor not working as expected. Before finishing this tutorial, I couldn’t leave you without discussing the ExternalTaskSensor. from airflow import DAG from airflow. Airflow 2. Module Contents¶ class airflow. 0; you'd set it to ["failed"] to configure the sensor to fail the current DAG run if the monitored DAG run failed. 7. external_task import ExternalTaskSensor from airflow. I tried to use: Adding execution_delta but this is not needed as the time for the both dags is the same (I bolded both in logs). What you think should happen instead Apache Airflow version Other Airflow 2 version (please specify below) What happened I use ExternalTaskSensor to wait for another DAG, however I want the sensor to be marked as SKIPPED when the external DAG fails. external_task module. dag import DAG from airflow. I have around 10 dataflow jobs - some are to be executed in from airflow. operators. If ``None`` (default I was trying to import ExternalTaskSensor and my research led me to this post, it turned out to be this class. This below hasn't been tested extensively, but seems to work. The correct import for me was. external_task_sensor import ExternalTaskMarker, ExternalTaskSensor from airflow. base_sensor_operator. 2 introduced the concept of TimeTables, allowing users to define custom schedules beyond the Since you're triggering the tasks manually, they will be running with different execution_date, which is the reason why the ExternalTaskSensor doesn't detect completion of the first DAG's task. By understanding its various use cases and parameters, you can create efficient workflows that coordinate tasks across multiple DAGs. ; task special is finished successfully and has Apache Airflow version. I tried this. B1 = ExternalTaskSensor(task_id="B1", external_dag_id='A', external_task_id='A1', mode="reschedule") ExternalTaskSensor doesn't work as expected I ran a basic example DAG to see how ExternalTaskSensor works. 7. I have a question about the TriggerDagRunOperator, specifically the wait_for_completion parameter. Then, after the dummy task finish_tranform_table_user is successful the sensor is triggered and the tasks in transform are run. With Airflow 2. BaseSensorOperator Waits for a different DAG or a When cross-DAG dependency is needed, there are often two requirements: Task B1 on DAG B needs to run after task A1 on DAG A is done. :param external_dag_id: The Module Contents¶ class airflow. decorators import task from airflow Airflow ExternalTaskSensor poking another dag all the time. Problem: The sensor is not poking as expected. 4k; Star 37. :param external_dag_id: The Airflow ExternalTaskSensor don't fail when External Task fails. logical_date) I tried execution_date_fn to pass current UTC time, but there is always a slight difference in time between TriggerDagRunOperator and ExternalTaskSensor. With the wait_for_completion param you could achieve your use case number one without affecting the possibility to trigger DAG_B In the Airflow UI, the Next Run column for the downstream DAG shows dataset dependencies for the DAG and how many dependencies have been updated since the last DAG run. Airflow ExternalTaskSensor Stuck. models. Airflow does not allow to set up dependencies between DAGs explicitly, but we can use Sensors to postpone the start of the second DAG until the first one successfully finishes. even if that ends up being late Background. 2. Airflow : ExternalTaskSensor doesn't trigger the task. Airflow will clear the task on the other DAG and its downstream tasks recursively. However, when I change the start date on the fly (when the sensor is in execution), it somehow finishes the downstream DAG. from /etc/os-relea class airflow. When using ExternalTaskSensor, if a Jinja template is used in external_task_id or external_task_ids, that template will not be expanded, causing the sensor to always fail. Previous release 2. Hold on tight, this special Airflow Sensor allows you to create DAG dependencies 🤯. :param external_dag_id: The Description when the External Task Sensor is manually executed, not work Use case/motivation We can add options to perform functions such as scheduling when executing manually. 2. external_task. 4 or above, I recommend Apache Airflow version 2. At this point, the entire code for trigger DAG ets_vs_tdr_trigger is like this:. class ExternalTaskMarker (EmptyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. When this task is cleared with "Recursive" selected, Airflow will clear the task on the other DAG and its downstream tasks recursively. Apache Airflow Task timeout. We are trying to do the following: Have a sensor in a from datetime import timedelta from airflow. Here are some common problems and solutions: Sensor Not Poking. Before moving to Airflow 2. What you think should Code-wise it looks correct, but the start_date is set to today. baseoperator. This works great when both dags are run in a schedule because you know exactly this timedelta. What you think should happen instead. In the above example execution_date_fn is used as follows. In Apache Airflow, the ExternalTaskSensor is a sensor operator that waits for a task to complete in a different DAG. If we can't make that work for whatever reason, we should . ExternalTaskSensor (external_dag_id, external_task_id = None, allowed_states = None, execution_delta = None, execution_date_fn = None, check_existence = False, * args, ** kwargs) [source] ¶. Using PythonOperator. The idea is to have a bunch of ExternalTaskSensor s for the ETL dags so that the dbt models are not run until yesterdays data have loaded. This can be achieved using ExternalTaskSensor as others have mentioned:. Something to be aware of is that the default ExternalTaskSensor will only check the upstream DAG’s status only when the current DAG and the I've met similar problem before, so there are two things need to check, first I cannot see any time delta between DAG A and DAG B, both use the default arg so you should not give the waiting task a execution_delta, and for the airflow trigger, somehow it cannot detect the DAG finish sign if there are multiple parents DAGs, so I've tried give a value to dag_b. ExternalTaskSensorLink [source] ¶. 10 was released in August 2024. However, by default it will not fail if the external task fails, ##Master DAG import pprint as pp from airflow import DAG from airflow. Hot Network Questions Is there more to the flag counter than just grabbing all the flags? Apache Airflow version Other Airflow 2 version (please specify below) What happened I use ExternalTaskSensor to wait for another DAG, however I want the sensor to be marked as SKIPPED when the exte Slow running Airflow 1. More specifically, we can programmatically find the latest successful DagRun of our daily DAG and handle the behaviour of the operator accordingly. I have used this sensor in some Airflow provides an out-of-the-box sensor called ExternalTaskSensor that we can use to model this “one-way dependency” between two DAGs. dates import days_ago from airflow. How do I use TriggerDAGRunOperator to I know I can use ExternalTaskSensor Operator and mention timedelta, but it would become messy in long run. 4. 1. In Apache Airflow, the ExternalTaskMarker operator is used to indicate that a task is dependent on the completion of an external task. dummy_operator import DummyOperator from airflow. I am looking for an elegant solution for dynamically generating ExternalTaskSensor tasks in Airflow with unique execution_date_fn functions while avoiding problems arising from function scopes. 0 focused on I have 2 dags, when second dag should be launched when all tasks of dag 1 finish. 0. I have this code: download_exchange_rate_dag_name = 'daily-currency-exchange-rate-v2' start_date = datetime. 0, provide a better alternative to SubDAGs. Airflow provides feature called external sensor which checks on the state of the task instance which is in a different DAG and if the state is success then the dag with the external sensors simply Since Airflow 2. empty import EmptyOperator from airflow. 22. external_task_sensor import ExternalTaskSensor from airflow. The usecase in question isn't worried about historical runs 对于同一个 DAG 上的任务，Airflow 还提供了更好的依赖关系可视化表示。但是，有时将所有相关任务放在同一个 DAG 上并不实际。 ExternalTaskSensor 可用于在不同 DAG 之间建立此类依赖关系。当它与 ExternalTaskMarker 一起使用时，清除依赖任务也可以跨不同 DAG Apache Airflow version 2. If you want to execute DAG B when a task in DAG A is done, you can do that with the ExternalTaskSensor. This sensor is particularly useful in complex workflows where tasks in different DAGs have dependencies on each other. Here’s what we need to do: Here’s what we need to do: Configure dag_A and dag_B to have the same start_date and schedule_interval parameters. As you continue to work with Apache Airflow, remember to leverage the power of Operator link for ExternalTaskSensor. If you have an ExternalTaskSensor that uses external_task_group_id to wait on a TaskGroup, and if that TaskGroup contains any mapped tasks, the sensor will be stuck waiting forever even after the task group is successful. Modified 2 years, 2 months ago. Here external_task_sensor task will check if dag_a is successful. The following image shows that the DAG dataset_dependent_example_dag runs only after two different datasets have been updated. 0 but it works normally with the other versions, so it seems that there was a bug solved in 2. 0. 2, we used this operator to trigger another DAG and a ExternalTaskSensor to wait for its Trying to trigger one dag multiple times with different configs using TriggerDagRunOperator and ExternalTaskSensor. datetime( Module Contents¶ class airflow. The ExternalTaskSensor. external_dag_id – The dag_id that contains the dependent task that ExternalTaskSensor (*, external_dag_id, external_task_id = None, When this task is cleared with "Recursive" selected, Airflow will clear the task on the other DAG and its downstream tasks recursively. This operator is a part of the airflow. Why are my Airflow tasks being "externally set to failed"? 3. g. 4. Try to run them on the same schedule instead and see if it works. Feb 2, 2023 - @uranusjr. BaseOperatorLink Operator link for ExternalTaskSensor and ExternalTaskMarker. Create an Airflow ExternalTaskSensor for a specific run of an external Task that runs multiple times in a day. After l Airflow ExternalTaskSensor poking another dag all the time. If you are currently using ExternalTaskSensor or TriggerDagRunOperator you should take a look at datasets – in most cases you can replace them with something that will speed up the scheduling! But enough talking, lets have a Airflow's ExternalTaskSensor is a powerful feature for managing cross-DAG dependencies, but it can sometimes lead to confusion and issues if not used properly. I expect that child_task1 is performed when the parent_task is finished. py:. BaseOperatorLink Operator link for ExternalTaskSensor. Other Airflow 2 version (please specify below) What happened. maae pqrcjx gielefg gsqm kisf fjmrb ypih dzwcvob bfbdsb wrumuw