Managed Airflow scheduler not working.

Question

Managed Airflow scheduler not working.

Milica Batinic 20 Microsoft Employee

We have a managed Airflow instance in our subscription, and the UI shows that the last heartbeat was a day ago (08/09). I tried resetting the Airflow instance multiple times, either by changing a variable or importing dags from a storage, and nothing worked. I also tried looking at logs, which yielded no results as well.

Help? I have no idea what to do next or how to fix this problem. Thanks. User's image

Smaran Thoomu 35,375 Reputation points Microsoft External Staff Moderator

2025-08-11T17:00:46.1066667+00:00

Hi Milica Batinic

Ensure that the version of Airflow you are using is compatible with any installed packages or dependencies, as certain packages can sometimes cause the scheduler to go offline. If there were any recent package installations, such as apache-airflow-providers, try uninstalling them, as they might be incompatible with the Airflow version managed by Azure.

I tried to reach you offline but you were not available. Since the Airflow scheduler heartbeat has been missing for more than a day and restarts haven’t resolved it, this indicates a possible backend service issue that cannot be fixed from the UI or configuration changes alone. I’ll reach out to the internal team to investigate this further for your Managed Airflow instance and will update you once I have more details.
Smaran Thoomu 35,375 Reputation points Microsoft External Staff Moderator

2025-08-12T09:52:54.6566667+00:00

Milica Batinic I kindly request you to provide the details mentioned in the private message so we can identify the root cause and address the issue effectively.

Answer accepted by question author

0 additional answers

Your answer

Smaran Thoomu 35,375 Reputation points Microsoft External Staff Moderator

2025-08-11T17:00:46.1066667+00:00

Hi Milica Batinic

Ensure that the version of Airflow you are using is compatible with any installed packages or dependencies, as certain packages can sometimes cause the scheduler to go offline. If there were any recent package installations, such as apache-airflow-providers, try uninstalling them, as they might be incompatible with the Airflow version managed by Azure.

I tried to reach you offline but you were not available. Since the Airflow scheduler heartbeat has been missing for more than a day and restarts haven’t resolved it, this indicates a possible backend service issue that cannot be fixed from the UI or configuration changes alone. I’ll reach out to the internal team to investigate this further for your Managed Airflow instance and will update you once I have more details.
Smaran Thoomu 35,375 Reputation points Microsoft External Staff Moderator

2025-08-12T09:52:54.6566667+00:00

Milica Batinic I kindly request you to provide the details mentioned in the private message so we can identify the root cause and address the issue effectively.

Answer 1

Hi Milica Batinic
Thank you for your patience. This issue was caused by a database schema migration conflict within the Managed Airflow service. Specifically, installing incompatible Airflow package versions (such as certain apache-airflow-providers dependencies) introduced an unrecognized alembic database migration revision, which prevented the scheduler from starting. This resulted in missing scheduler heartbeats and failure of newly created instances as well.

Resolution:

The root cause was identified as a dependency conflict that caused the Airflow database to migrate into an unsupported state.
The affected instances were recovered by updating the alembic versioning table to remove the unrecognized migration revision.
After this corrective action, the scheduler heartbeat resumed, and both new and existing Airflow instances became operational.

Recommendations:

Ensure that only supported Python packages and Airflow provider versions are installed in Managed Airflow. Incompatible packages may cause database and scheduler failures.
If the issue recurs, please open a support ticket so the backend team can validate and remediate.

This incident has now been resolved, and the affected Managed Airflow instances are running as expected.

Hope this helps. Do let us know if you any further queries.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Share via

Managed Airflow scheduler not working.

0 additional answers

Your answer