How to restart a stuck Airflow DAG
Occasionally, Airflow DAGs get stuck in the running state but don’t want to run any tasks. From my observations, it happens mostly when we clear many DAG runs in one DAG because we want to reprocess a large number of tasks.
To avoid this problem, I suggest using the backfill command to restart only a small subset of DAGS. For example, a week of work, wait until it finishes, and restarting another batch.
Anyway, what to do when it is too late, and we have already ended up in a situation when everything is running
, but nothing actually wants to run.
The first thing we can do is using the airflow clear
command to remove the current state of those DAG runs. We can specify the date range using the -s
and -e
parameters:
1
airflow clear -s 2020-01-01 -e 2020-01-07 dag_id
When that is not enough, we need to use the Airflow UI. In the menu, click the ‘Browse” tab, and open the ‘DAG Runs’ view.
On this page, we should find the DAG runs that don’t want to run, select them, and click the ‘With selected’ menu option. In the new menu, we click the ‘Delete’ command.
After that, Airflow should recreate the missing task instances and perhaps starts to execute the code.
Did you enjoy reading this article?
Would you like to learn more about software craft in data engineering and MLOps?
Subscribe to the newsletter or add this blog to your RSS reader (does anyone still use them?) to get a notification when I publish a new essay!
You may also like
- Use HttpSensor to pause an Airflow DAG until a website is available
- How to define an AWS Athena view using Airflow
- How to check the next execution date of an Airflow DAG
- How to use Virtualenv to prepare a separate environment for Python function running in Airflow
- Remove a directory from S3 using Airflow S3Hook

Bartosz Mikulski
- Data/MLOps engineer by day
- DevRel/copywriter by night
- Python and data engineering trainer
- Conference speaker
- Contributed a chapter to the book "97 Things Every Data Engineer Should Know"
- Twitter: @mikulskibartosz
- Mastodon: @mikulskibartosz@mathstodon.xyz