I have a running dag, Can I stop it using REST API ?
There is a method to delete a running dag:
https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/delete_dag_run。
But There is not REST API how to stop a running dag?
Thanks!
You can set the running tasks to failed with Set a state of task instances note that this will stop the task from running and set the task status to failed but it will not invoke the on_failure_callable if you set one on your tasks nor it will invoke the on_kill method of the operator (if there is one).
If you want the DAG to not schedule any more tasks you can set it to Pause with Update a DAG
Related
I have two DAGs in my airflow scheduler, which were working in the past. After needing to rebuild the docker containers running airflow, they are now stuck in queued. DAGs in my case are triggered via the REST API, so no actual scheduling is involved.
Since there are quite a few similar posts, I ran through the checklist of this answer from a similar question:
Do you have the airflow scheduler running?
Yes!
Do you have the airflow webserver running?
Yes!
Have you checked that all DAGs you want to run are set to On in the web ui?
Yes, both DAGS are shown in the WebUI and no errors are displayed.
Do all the DAGs you want to run have a start date which is in the past?
Yes, the constructor of both DAGs looks as follows:
dag = DAG(
dag_id='image_object_detection_dag',
default_args=args,
schedule_interval=None,
start_date=days_ago(2),
tags=['helloworld'],
)
Do all the DAGs you want to run have a proper schedule which is shown in the web ui?
No, I trigger my DAGs manually via the REST API.
If nothing else works, you can use the web ui to click on the dag, then on Graph View. Now select the first task and click on Task Instance. In the paragraph Task Instance Details you will see why a DAG is waiting or not running.
Here is the output of what this paragraph is showing me:
What is the best way to find the reason, why the tasks won't exit the queued state and run?
EDIT:
Out of curiousity I tried to trigger the DAG from within the WebUI and now both Runs executed (the one triggered from the WebUI failed, but that was expected, since there was no config set)
We have encountered a scenario recently where someone mistakenly turned off a production dag, and we want to get alert whenever a dag is paused using datadog.
I have checked https://docs.datadoghq.com/integrations/airflow/?tab=host
But have not got any metric for dag to check if it is paused or not.
I can run a custom script in datadog as well.
One of the method is that I exec into postgres pod and get the list of active dags:
select * from dag where is_paused=true;
Or is there any other way I can get the unpaused dag list and also when new dag is added what is the best way to handle it.
I want the alert whenever a unpaused dag is paused.
If you are on Airflow 2 you can use the REST API to query for state of the DAG.
https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/get_dag
There is "is_paused" field.
And of you are not Airflow 2, you should be. Airflow 1.10 is end-of-life and will not receive any fixes (including critical security fixes) so you should upgrade as soon as you can.
I have a task in Airflow that uses bash operator which is running continuously.
Is there any way to make the task instance as success before its next scheduled run? I know how to mark it as success in api.
Thank you for your replies
If you just want to call the api automatically to mark the previous dagrun as success, you can use SimpleHttpOperator as the first task of your dag. This operator might call airflow REST API to request to mark the previous dagrun as success.
https://airflow.apache.org/docs/apache-airflow-providers-http/stable/operators.html#simplehttpoperator
What would happen if DAG changes while DAG is running (particularly if this is dynamic DAG)
What would happen if code of custom made operator is changed during some DAG run
So after some investigation I came to conclusion that DAG changes will be visible in current DAG run and that operators (and all other plugins) are not reloaded by default.
DAG changes during DAG run
If you remove task while DAG is running scheduler notice that, set status for that task to "Removed" while logging current line:
State of this instance has been externally set to removed. Taking the poison pill.
If you add new task it will also be visible and executed. It will be executed even if it is upstream task of task which is already finished
If task is changed, changes will be incorporated into current DAG run only if task is not already started execution or finished
All plugins (included operators) are not refreshed automatically by default. You can restart Airflow or you can set reload_on_plugin_change property in [webserver] section of airflow.cfg file to True
I need to restart Airflow. I want to make sure I do it when it's idle, so I that I don't interrupt a job by restarting the worker component of Airflow.
How do I see what DAGs are running?
I don't see anything in the UI that would list currently running DAGs.
I don't see any command in the airflow CLI to list currently running DAGs.
I found airflow shell that lets me connect to the DB, but I don't know enough about Airflow internals to know where to look to see what's running.
You can also query the database to get all running tasks at once:
select * from task_instance where state='running'
You can use the command line command airflow jobs check which would return "No alive jobs found." in the event no jobs are running.
I found it... it's in the UI, on the DAGs page, it's the second circle under "Recent Tasks":