Externaltasksensor airflow 2. Hence, if you’re utilizing an Airflow version of 2.
Externaltasksensor airflow 2 A sensor that only relies on the most recent run to be in allowed_states instead of using a execution_delta or execution_delta_fn. Since that's class airflow. The Overflow Blog Even high-quality code can lead to tech debt. Source code for airflow. Airflow ExternalTaskSensor with different scheduler interval. It is making the process complicated. How to trigger DAG in Airflow everytime an external event state is True (Event based triggering) Related. settings Airflow 1. Improve this answer. If ``None`` the sensor waits for the 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. Export Airflow run id , dag id ,execution date etc variable to Bigquery table. To make a task in a DAG wait for another task in a different DAG for a specific execution_date, you can use the ExternalTaskSensor as follows:. 2 + the CeleryExecutor. What is the problem with the provide_context? To the best of my knowledge it is needed for the usage of params. base_sensor_operator import BaseSensorOperator as \ BaseSensorOperatorImp from airflow. Apache Airflow version 2. BaseSensorOperator Waits for a different DAG or a If no timeout is set and some of our dependencies fail, the sensors will run indefinitely and cause your airflow to hang. Airflow - Dynamic Tasks and Downstream Dependencies. 2; Airflow components and configuration: Running with CeleryExecutor (separate docker containers running webserver, worker, rabbitmq and mysql db) Is it possible to write down all DAGs and descriptions like DAG A has TriggerDagRunOperator, DAG B has ExternalTaskSensor and schedule or any relative config of all DAGs mentioned in here? I cannot picture it well yet. 23. Airflow ExternalTaskSensor poking another dag all the time. ExternalTaskSensorLink. 2 airflow stops scheduling dagruns after task failure. 0 if you use the retry_delay=30 (or any other number) parameter with the ExternalTaskSensor, the DAG will run just fine, until you want to clear the task instance Apache Airflow version. Hot Network Questions Is there more to the flag counter than Trying to trigger one dag multiple times with different configs using TriggerDagRunOperator and ExternalTaskSensor. This can happen when trying to Module Contents¶ class airflow. below are the params for your reference sensor_run_initial = ExternalTaskSensor(task_id='dag_sensor_for_run_initial', external_dag_id='RunInitial', external_task_id=None, dag=dag ) Please tell me if any thing need to be changed in the Apache Airflow version 2. ; task special is finished successfully and has I tried the way you stated and the dag sensor still in running state even though the dag has ran successfully. What happened. sensors. However, when a dag is triggered manually or by another dag, you cannot known for sure the the exact execution date I know I can use ExternalTaskSensor Operator and mention timedelta, but it would become messy in long run. They allow you to group tasks together in a visually appealing way without the execution overhead of SubDAGs. Airflow using ExternalTaskSensor Operator caused MySQL innodb deadlock. external_task import ExternalTaskMarker, ExternalTaskSensor. If we can't make that work for whatever reason, we should The timeout is OK to be 90 seconds, as the test_dag_son is finishing within less than 30 seconds. For Airflow 2. Sign in Bases: airflow. 0 Kubernetes version (if you are using kubernetes) (use kubectl version): 1. 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 short Code-wise it looks correct, but the start_date is set to today. 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. Apache Airflow version. The Airflow API. external_task import ExternalTaskSensor The documentation page is here which shows its usage (specifying execution dates, success states etc. ExternalTaskSensor can be used to establish such Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I was trying to import ExternalTaskSensor and my research led me to this post, it turned out to be this class. 0 Add new DAG to airflow scheduler. Using PythonOperator. It for some operators in dags B and C it takes too long, I'd like to continue without "hanging" operators and use whatever data I received so far. This sensor is particularly 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 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. BaseSensorOperator class airflow 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. session import provide_session class SmartExternalTaskSensor(ExternalTaskSensor): # Something a bit odd happens with ExternalTaskSensor when run as a smart # sensor. 6. dates import days_ago from airflow. For example: how set two DAGs in airflow using ExternalTaskSensor? 3. I want to include an ExternalTaskSensor in DAG2 so that the computations are reliably performed after the data I have tracked down the issue to the _get_count function. I have around 10 dataflow jobs - some are to be executed in . 0 but it works normally with the other versions, so it seems that there was a bug solved in 2. 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 The ExternalTaskSensor is designed for this. g. 17. Airflow will clear the task on the other DAG and its downstream tasks recursively. Try to run them on the same schedule instead and see if it works. Airflow DAG Multiple Runs. 4 or above, I recommend Airflow 2. To clear dependent tasks, you would need to clear the ExternalTaskMarker task. Then, after the dummy task finish_tranform_table_user is successful the sensor is triggered and the tasks in transform are run. Airflow setting conditional dependency. ExternalTaskSensor with multiple dependencies in Airflow. Share. Below is the code for. 5. Airflow, calling dags from a dag causes duplicate dagruns. 3. 6. 0; you'd set it to ["failed"] to configure the sensor to fail the current DAG run if the monitored DAG run failed. Stack Overflow. 2, we started getting a ZeroDivisionError the first time some ExternalTaskSensor were poked Support for passing such arguments will be dropped in Airflow 2. 1. 1 I first installed Amazon provider: pip install apache-airflow-providers-amazon and We're proud to announce that Apache Airflow 2. external_dag_id – The dag_id that contains the dependent task that needs to be cleared. 10, you can set skip_when_already_exists to True to keep the operator from attempting to trigger runs that have already occurred, and failing as a result. SENSORS. Problem: The sensor is not poking as expected. deactivate_stale_dags_interval has been renamed to scheduler. skipmixin. 0, I think there is no need to use ExternalTaskSensor. 0 increases the minimum supported version of I am new to Airflow and am encountering this issue - I have two DAGs in two separate files, wherein the second one should run after the first one has finished. What happened? Using a deferred ExternalTaskSensor to wait against a TaskGroup will not complete until the external_dag_id specified in the sensor is complete. The Dag Dependencies view Menu-> Browse-> # from airflow. Four approaches to creating a 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 Since Airflow 2. external_task import ExternalTaskSensor Just FYI in case anyone runs into this in the future. Add a comment | 8 With the advent of TaskGroups in Airflow 2. Hot Network 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. 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. dates import days_ago start_date = days_ago(1) # run the day zero once, then start running incremental with DAG(dag_id="dayzero_dag", We've made extensive use of [ExternalTaskSensor][1] to the point where the quantity of cross-dag dependencies have become difficult to track. hdfs_sensor 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. 2 Airflow - How to configure that all DAG's tasks run in 1 worker. Yes, you heard it right. Use this operator to indicate that a task ExternalTaskSensor( task_id = "wait_sensor", external_dag_id="dag_b", external_task_id = "end", mode="reschedule", timeout=60*60*23, retries = 10, When dependencies arise between these DAGs, such as the requirement for DAG B (dag_b) to execute only after the successful completion of DAG A (dag_a), we leverage Airflow’s ExternalTaskSensor to verify dag_a’s Airflow provides an out-of-the-box sensor called ExternalTaskSensor that we can use to model this “one-way dependency” between two DAGs. If ``None`` (default Background. If you want to execute DAG B when a task in DAG A is done, you can do that with the ExternalTaskSensor. models import DAG from airflow. 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. Airflow scheduler periodically complains no heartbeat. external_task import ExternalTaskSensor from airflow. 0 why Airflow PythonOperator task failed but return code is AirflowException is now thrown as soon as any dependent tasks of ExternalTaskSensor fails (#27190) The Airflow config option scheduler. About; timedelta from pprint import pprint from airflow import DAG from airflow. 2 Content. Here are some common problems and solutions: Sensor Not Poking. However, by default it will not fail if the external task fails, but will continue to check the status until the sensor times out (thus giving you time to retry the external task without also having to clear In this case, ExternalTaskSensor will raise AirflowSkipException or AirflowSensorTimeout exception """ from __future__ import annotations import pendulum from airflow. For example: Two DAGs may have different schedules. 0, provide a better alternative to SubDAGs. Add a retry in my task, but that would not make sense if the external dag truly fails Module Contents¶ class airflow. Different task schedules. ##Master DAG import pprint as pp from airflow import DAG from airflow. If ``None`` (default class ExternalTaskMarker (DummyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. 1, the Apache Airflow version. ExternalTaskSensor requires Operator link for ExternalTaskSensor and ExternalTaskMarker. How do I set up Airflow DAG permissions to query a BigQuery table that is built on top of a Google Sheets doc? 2. baseoperator. operators. ExternalTaskMarker. 0 How to Write a DAG with Multiple Similar Apache Airflow version: 2. SkipMixin Sensor operators are derived from this class and inherit these attributes. 2 introduced modes in sensors mode='poke' (default) means the existing behaviour that we discussed above; mode='reschedule' means after a poke attempt, rather than going to sleep, the sensor will Slow running Airflow 1. Perhaps what you're looking for instead is the TriggerDagRunOperator. Load 4 more related questions Show fewer related questions Sorted by: Reset to default Browse other questions tagged . 0 beta3 with Docker Compose Cloud provider or hardware configuration: OS (e. This can be achieved using ExternalTaskSensor as others have mentioned:. If ``None`` (default I just tested your code with airflow from 2. from /etc/os-relea In fact too many having ExternalTaskSensors is notorious for putting entire workflows (DAGs) into deadlocks; To overcome this problem, Airflow v1. 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. Viewed 10k times 7 Colleagues, we need help. With the wait_for_completion param you could achieve your use case number one without affecting the possibility to trigger DAG_B The Apache Airflow ExternalTaskSensor is a powerful and versatile tool for managing cross-DAG dependencies in your data pipelines. This sensor functions correctly when the external DAG exists (normal operation I removed execution_delta and set the schedule_interval to 0 1 * * *. Airflow execute task in sequence without defining dependency. 0 ExternalTaskSensor retry_delay=30 yields TypeError: can't pickle _thread. My second DAG (DAG2) performs computations on data loaded by DAG1. Sensor operators keep executing at a time interval and succeed when a criteria is met and fail if and when they time out. 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). I expect that child_task1 is performed when the parent_task is finished. ExternalTaskSensor (external_dag_id, external_task_id, allowed_states=None, execution_delta=None, execution_date_fn=None, check_existence=False, *args, **kwargs) [source] ¶. Additional difficulty is that one DAG could wait for or trigger several runs of the other DAG with different execution dates. ExternalTaskSensor also provide options to Use this operator to indicate that a task on a different DAG depends on this task. ExternalTaskSensor( task_id='sensor', dag=dag, external_dag_id='DAG2', external_task_id='sensed_task', mode='reschedule', check_existence=True, execution_delta=timedelta(hours=int(execution_type)), poke_interval=10 * 60, # Check every 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. 3. What you think should Airflow also offers better visual representation of dependencies for tasks on the same DAG. 0 Monitor Multiple Airflow instances. 1 airflow on_failure_call_back continuously running now. With Airflow 2. 7. external_task. 0b3 (Docker) Kubernetes version (if you are using kubernetes) (use kubectl version): N/A Environment: Airflow 2. 4 Content. execution_date_fn is used to calculate desired execution date according to current execution date if execution_delta is not passed, in current stable version 1. ExternalTaskSensor¶ Use the ExternalTaskSensor to make tasks on a DAG wait for another task on a different DAG for a specific execution_date. Hold on tight, this special Airflow Sensor allows you to create DAG dependencies 🤯. 2 TriggerDagRunOperator wait_for_completion behavior. Transitive dependencies are followed until the recursion_depth is reached. Here's an example: In Apache Airflow, the ExternalTaskSensor is a sensor operator that waits for a task to complete in a different DAG. When this task is cleared with "Recursive" selected, Airflow will clear the task on the other DAG and its downstream tasks recursively. 2 Airflow does not trigger concurrent DAGs with `LocalExecutor` 29 Airflow: Creating a DAG in airflow via UI. I want that to wait until completion and next task should trigger based on the status. This can be used to establish dependencies across 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 Situation: Airflow 1. 22. base_sensor_operator. Apache Airflow - ExternalTaskSensor,how do we use 'execution_date_fn' to return execution_date. In Apache Airflow, the ExternalTaskMarker operator is used to indicate that a task is dependent on the completion of an external task. In this case, ExternalTaskSensor keeps running forever since it is poking to instance with execution_date as master DAGs execution_date (i. 3 running on a Kubernetes pod, LocalExecutor, parallelism=25 Every night our DAGs will start their scheduled run, which means lots of tasks will be running in parallel. Airflow ExternalTaskSensor gets stuck. Version of Airflow: v1. 7. Airflow scheduler stuck. external_task_sensor import ExternalTaskSensor as \ ExternalTaskSensorImp from airflow. Timeout should be calculated based on current run start_date and not start_date from previous runs which can range from any day Apache Airflow version. Other Airflow 2 version (please specify below) What happened. Can I use a III. The ExternalTaskSensor. 0 Airflow: how to mark ExternalTaskSensor operator as Success after timeout. After l Module Contents¶ class airflow. Home; Project; License; Quick Start; Installation Apache Airflow version. Automatically generating ExternalTaskSensor where execution date depends only on DAG id. However, when I change the start date on the fly (when the sensor is in execution), it somehow finishes the downstream DAG. 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. ExternalTaskSensor (external_dag_id, external_task_id = None, allowed_states = None, execution_delta = None, execution_date_fn = None, check_existence = False, * args, ** kwargs) [source] ¶. external_task_sensor import ExternalTaskSensor # from airflow. Extracting this info would allow us to By default the ExternalTaskSensor will monitor the external_dag_id with the same execution date that the sensor DAG. main (development) If "Other Airflow 2 version" selected, which one? No response. dates from datetime import datetime, timedelta """[ This File contains code for cross dag dependencies class ExternalTaskMarker (DummyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. Thus, I have a timeout, and I'd like to mark my ExternalTaskSensors as Apache Airflow version: 2. 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 ExternalTaskSensor in Airflow UI and Re-direct button. ; I ran the test_dag_father using schedule. BaseOperatorLink Operator link for ExternalTaskSensor. 5 and 2. Commented Jun 1, 2022 at 14:45. e. a weekly DAG may have tasks that depend on other tasks on a daily DAG. example_external_task_marker_dag # # Licensed to the Apache Software Foundation (ASF) under one # or more contributor license Added in Airflow 2. Bases: airflow. ; Solution: Ensure that the poke_interval is set correctly and that the sensor's mode is not set to Module Contents¶ class airflow. 0. This works great when both dags are run in a the same schedule or when you know exactly the timedelta between the two. 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. 4. 1. how set two DAGs in airflow using ExternalTaskSensor? 3 Airflow on demand DAG with multiple instances running at the sametime. external_dag_id – The dag_id that contains the dependent task that needs to be import datetime from airflow. So instead of relying on polling, you can use You could also use ExternalTaskSensor but beware that as the number of dags grow, it might get harder to handle external dependencies between tasks. New Features; Improvements; Bug Fixes; Misc/Internal; Doc only changes; Airflow 2. BaseOperator, airflow. ). # Until then this class . 1! You can check and follow the issues with the PostgresOperator in the links provided under references [4, 5 In this case, ExternalTaskSensor will raise AirflowSkipException or AirflowSensorTimeout exception """ import pendulum from airflow import DAG from 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. sensors import external_task sensor = external_task. Still, it didn't trigger the DAG when upstream one got finished. It allows users to access DAG waited with ExternalTaskSensor. Content. BaseSensorOperator [source] ¶. 2. In this section, you'll learn how and when you should use each method and how to view dependencies in the Airflow UI. how to operate in airflow so that the task rerun and continue downstream tasks. 1 What happened If a DAG (dag1) is running and another DAG (dag2) has an ExternalTaskSensor (task-externalsensor) that checks a task on dag1, task-externalsensor will fail unless dag1's task finishes in under 6 Create an Airflow ExternalTaskSensor for a specific run of an external Task that runs multiple times in a day. 2 ETL when using ExternalTaskSensor for DAG task dependency? Airflow ExternalTaskSensor doesn't recognise task in DAG is on status SUCCESS. I think subdags might be the way to go for your use case. In Airflow 1. 9. I have used this sensor in some Operator link for ExternalTaskSensor. Ask Question Asked 5 years, 2 months ago. Related. And context is not include a session, so you could not query database in it. 0 to 2. I. Is there any other solution to fix this? If I trigger the master dag again, I want the task to restart from where it is failed. With execution_delta set, the ExternalTaskSensor will check for the task with execution date execution_date - execution_delta. Use ExternalTaskSensor between the trigger calls to wait for the last task of the previous DAG. 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 That's expected behavior. Create an Airflow ExternalTaskSensor for a specific run of an external Task that runs multiple times in a day. 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. Module Contents¶ class airflow. Hot Network Questions How to teach high school students to analyze diagrams in a proof? Meaning of Second line of Shakespeare's Sonnet 66 Inventor builds "flying doughnut" time machine Why is ExternalTaskSensor (*, external_dag_id, external_task_id = None, external_task_ids = None, Airflow will clear the task on the other DAG and its downstream tasks recursively. parsing_cleanup_interval (#27828). decorators import task from airflow Airflow: ExternalTaskSensor doesn't work as expected. postgres_operator import PostgresOperator from datetime import datetime, timedelta from airflow. 16. Airflow trigger tasks only Apache Airflow version 2. If you somehow hit that number, airflow will not process further tasks. This operator is a part of the airflow. Overview; Project; License; Quick Start; Installation Dear Airflow Maintainers, Before I tell you about my issue, let me describe my environment: Environment. external_task_sensor. Last week you wrote a job that peforms all the necessary processing to build your sales table in the database. Airflow XCom - how to share vars between DAGs using TriggerDagRunOperator? 7. TaskGroups are just UI groupings for Operator link for ExternalTaskSensor and ExternalTaskMarker. Unable to run Airflow Tasks due to execution date and start date. To configure the sensor, we need the identifier of another DAG (we will wait until that DAG finishes). What you think should happen instead. airflow; Share. airflow; or ask your own question. ExternalTaskSensorLink [source] ¶. Invalid arguments were: *args: () **kwargs: {'provide_context': True} category=PendingDeprecationWarning. 0. from airflow. from airflow import DAG from airflow. Ask Question Asked 7 years, 4 months ago. 3, it didn't work with 2. If "Other Airflow 2 version" selected, which one? No response. ExternalTaskSensorLink By default the ExternalTaskSensor will wait for the external task to succeed, at which point it will also succeed. python_operator import PythonOperator # from airflow. 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. 0 Airflow cross dag dependency. ExternalTaskSensor can also sense an entire DAG (instead of a specific task of the DAG) Airflow marks a DAG failed if any one of it's leaf tasks fail (in other words, Airflow marks a DAG success only if all leaf tasks succeed) you can do it without adding any dummy task in 1st DAG Airflow externaltasksensor not working as expected. This is because airflow only allows a certain maximum number of tasks to be run on an instance and sensors are considered as tasks. 10. Help me crack this one. By default it checks every minute, but you can lower this interval by setting poke_interval (seconds) on the sensor. external_task import ExternalTaskMarker, ExternalTaskSensor I am using airflow version 2. Waits for a different DAG, a task group, or a task in a different DAG to complete for a. :param external_dag_id: The 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. Modified 2 years, 2 months ago. When this task is cleared with “Recursive” selected, Airflow will clear the task on the other Operator link for ExternalTaskSensor and ExternalTaskMarker. At this point, the entire code for trigger DAG ets_vs_tdr_trigger is like this:. 2. external_task_sensor import ExternalTaskSensor import airflow. In Apache Airflow, a defined DAG/workflow can wait for another DAG until it is success, failed, or queued by defining a task on the beginning of the DAG that must wait using TaskGroups, introduced in Airflow 2. Your description means that you 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. Airflow ExternalTaskSensor Stuck. However, it is sometimes not practical to put all related tasks on the same DAG. There are two dags Parent and Child, parent has its own schedule, suppose '30 * * * * ', child '1 8-17 * * 1-5', child waits for parent to execute, for example 40 I plan to use TriggerDagRunOperator and ExternalTaskSensor . I have a question about the TriggerDagRunOperator, specifically the wait_for_completion parameter. Skip to main content. utils. However, the typing suggests this shou Using 'ExternalTaskMarker' to Clear Dependent Tasks in Apache Airflow. Modified 5 years, 7 months ago. E. Ask Question Asked 3 years, 9 months ago. 2, we used this operator to trigger another DAG and a ExternalTaskSensor to wait for its Module Contents¶ class airflow. This can be useful in scenarios where you have dependencies across different DAGs. from failed_states was added in Airflow 2. This works great when both dags are run in a schedule because you know exactly this timedelta. Parameters. airflow sensor timeout not reached. Modified 5 years, 2 months ago. Is there any easy/clean option with TriggerDAGRunOperator to check everyday if DAG 2 is indeed scheduled to run for that day then only trigger it else skip it on other days? class ExternalTaskMarker (EmptyOperator): """ Use this operator to indicate that a task on a different DAG depends on this task. empty import EmptyOperator from airflow. Airflow DAG does not run at specified time with catchup=False. – Apache Airflow version 2. Each task is either a KubernetesPodOperator starting the actual work on another pod or an ExternalTaskSensor that waits for another task to be completed (in the ETL Navigation Menu Toggle navigation. from /etc/os-relea 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. While dependencies between tasks in a DAG are explicitly defined through upstream and downstream relationships, dependencies between DAGs are a bit more complex. DAG does not recognize tasks Airflow. This sensor is particularly useful in complex workflows where tasks in different DAGs have dependencies on each other. According to the docs, an external task sensor waits for a different DAG or a task in a different DAG to # -----# # #TODO #FIXME Airflow 2. 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. I thought of two solutions to solve this issue. x, it's worth expanding on a previous answer. 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. Use this operator to indicate that a task on a different DAG depends on this task. I tried to add soft_fail ExternalTaskSensor (*, external_dag_id, external_task_id = None, external_task_ids = None, Airflow will clear the task on the other DAG and its downstream tasks recursively. Airflow - External task sensor running on different hour. Airflow: ExternalTaskSensor doesn't work as expected. :param external_dag_id: The Define an ExternalTaskSensor in DAG_A that senses the completion of Task_B in DAG_B. This external link is deprecated. 0, sensors can be set to deferrable mode, which allows the sensor to release the By default the ExternalTaskSensor will monitor the external_dag_id with the same execution date that the sensor DAG. 4. . How 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. Starting with Airflow version 2. 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 Create an Airflow ExternalTaskSensor for a specific run of an external Task that runs multiple times in a day. your might try from airflow. Ideally the template should be expanded. ExternalTaskSensor can be used to establish such Description. 0 is a big thing as it implements many new features. class airflow. 0 # # In Airflow this will be moved to the airflow. BaseSensorOperator Waits for a different DAG or a I tried this. The correct import for me was. Since we FAIL the DAG with External Task Sensor when executi I have a dag A, which is waiting for some other operators in other dags B and C to download the data, and then performs come computations on it. 1 Airflow DAG tasks parallelism on different worker nodes. More specifically, we can programmatically find the latest successful DagRun of our daily DAG and handle the behaviour of the operator accordingly. DAG_A: with DAG( dag_id="dag_a", default_args=DEFAULT_ARGS, max_active_runs=1, schedule_interval="15 2 * * *", catchup=True ) as dag: dummy_task = DummyOperator(task_id="Task_A") how set two DAGs in airflow using ExternalTaskSensor? 0 how to achieve more complicated dag 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. In this case Airflow ExternalTaskSensor with different scheduler interval. Airflow sensor As the titles says; in Airflow 1. 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. Viewed 2k times 1 If the upstream dags are triggered dynamically, they are assigned granular 'execution_date' rather than dd-mm-yyyy hh:00:00 as the scheduler would assign. from datetime import timedelta from airflow. Airflow ExternalTaskSensor don't fail when External Task fails. Right now, it's not restarting, but for time based schedule,it will. How to use Airflow ExternalTaskSensor In Apache Airflow, the ExternalTaskSensor is a sensor operator that waits for a task to complete in a different DAG. 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 Content. 1 What happened When running an ExternalTaskSensor with external_task_id=None and in deferrable mode, the trigger doesn't wait for the entire DAG since it needs a task_id. What you think should happen instead? In Airflow 2, you can do a dynamic task mapping. 10, there is param check and it accept at most 2 args, context['execution_date'] and context. 10. how set two DAGs in airflow using ExternalTaskSensor? 0. BaseSensorOperator Waits for a different DAG or a Operator link for ExternalTaskSensor. external_task_sensor import ExternalTaskMarker, ExternalTaskSensor from airflow. The first DAG (DAG1) is a long-running data load from s3 into Redshift (3+ hours). 1 Trying to run same airflow task Apache Airflow version. python_operator import PythonOperator from custom_sensors import get_execution_date_of_dependent_dag default_args = {'owner': 'airflow', 'depends_on_past': False, 'start_date': datetime(2023, 1, 1) But we will be able to access the resolved values in ninja template in airflow 2. Why does Airflow ExternalTaskSensor not work on the dag having I have two DAGs that I need to run with Airflow 1. external_dag_id – The dag_id that contains the dependent task that needs to be ExternalTaskSensor (*, external_dag_id, external_task_id = None, external_task_ids = None, Airflow will clear the task on the other DAG and its downstream tasks recursively. sensors package. models. Airflow 2. ExternalTaskSensor. 9. RLock objects. external_dag_id -- The dag_id that contains the dependent task that needs to be cleared. – Emma. Waits for a different DAG, task group, or task to complete for a specific logical date. dummy_operator import DummyOperator from airflow. Improve this DummyOperator doesn't have any actual code to execute so it's redundant to submit it to run on worker due to that reason Airflow has optimization that DummyOperator and any of its subclasses will not be sent to workers, they are automatically marked as Success by the scheduler (assuming no on_execute_callback is called etc. By understanding its various use cases and parameters, you can create efficient workflows that coordinate tasks across multiple DAGs. If given a task ID, it'll monitor the task state, otherwise it monitors DAG run state. Before moving to Airflow 2. Instantiate an instance of ExternalTaskSensor in dag_B pointing towards a specific task of dag_A nd set it as an upstream dependency of the first task(s) in your pipeline. 0 has been released with many exciting improvements. Airflow DAGs failed to be triggered. Airflow ExternalTaskSensor execution timeout. 2 What happened After upgrading to version 2. Came across ExternalTaskSensor. Airflow : ExternalTaskSensor doesn't trigger the task. Here’s what we need to do: To address these cross-DAG dependencies, Airflow provides the ExternalTaskSensor, a built-in sensor that monitors the status of a task in another DAG and triggers subsequent tasks when 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. Before finishing this tutorial, I couldn’t leave you without discussing the ExternalTaskSensor. The second approach involves a more customised solution. Follow Airflow ExternalTaskSensor poking another dag all the time. x, unfortunately, the ExternalTaskSensor operation only compares DAG run or task state against allowed_states; Operator link for ExternalTaskSensor and ExternalTaskMarker. :param external_dag_id: The Airflow: ExternalTaskSensor doesn't work as expected. How can you re-run upstream task if a downstream task fails in Airflow (using Sub Dags) 3. The test_dag_son shouldn't have any schedule. Version: 2. Users of TriggerDagRunOperator or ExternalTaskSensor may know the pain of going from one DAG to the other one referenced by the ExternalTaskSensor doesn't work as expected I ran a basic example DAG to see how ExternalTaskSensor works. 18 Environment: Linux Cloud provider or hardware configuration: AWS OS (e. external_task module. What happened? For ExternalTaskSensor, when I specify deferrable=True and failed_states=["failed"], the operator hangs in deferred mode and repeatedly pokes the upstream DAG status. This can be done 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. This works fine if I don't use deferrable. dagrun_operator import TriggerDagRunOperator from 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. As you continue to work with Apache Airflow, remember to leverage the power of the ExternalTaskSensor to You are an analyst/data engineer/data scientist building a data processing pipeline in Airflow. B1 = ExternalTaskSensor(task_id="B1", external_dag_id='A', external_task_id='A1', mode="reschedule") from airflow. dag import DAG from airflow. 'dag_2']: sensor = ExternalTaskSensor( task_id='sense_'+dag_id, external_dag_id=dag_id, execution_date_fn=lambda dt: Airflow also offers better visual representation of dependencies for tasks on the same DAG. The ExternalTaskSensor is polling for DAG datamart_OTT_CMS_v1's "end" task to be complete. 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. Viewed 7k times 4 I am trying to create an External Sensor (in DAG B) on a task in a different DAG (let's call this as DAG A) which runs at following intervals: 'schedule_interval': '0 Operator link for ExternalTaskSensor and ExternalTaskMarker. How to combine multiple DAGs in Airflow. I can think of couple potential issues with this: we may need to sort the task_instance tables based on execution_date, can be expensive; a race condition, where when our sensor is poking the external task is not Airflow : ExternalTaskSensor doesn't trigger the task. example_dags. For that, I have used ExternalTaskSen Apache Airflow version 2. eytahde ycwk seuwt bek rrl xbyvgqu rpxpi gxt jodk cbw