Calendar view infinite loop for @continuous DAGs

[tanelk]

Apache Airflow version

main (development)

If "Other Airflow 2 version" selected, which one?

No response

What happened?

The /dags/<string:dag_id>/calendar view does not open for DAGs, that have schedule='@continuous'.

It happens because this loop in airflow.www.views.Airflow.calendar is practically infinite.

while True:
    curr_info = dag.timetable.next_dagrun_info(
        last_automated_data_interval=last_automated_data_interval,
        restriction=restriction,
    )
    if curr_info is None:
        break  # Reached the end.
    if curr_info.logical_date <= prev_logical_date:
        break  # We're not progressing. Maybe a malformed timetable? Give up.
    if curr_info.logical_date.year != year:
        break  # Crossed the year boundary.
    last_automated_data_interval = curr_info.data_interval
    dates[curr_info.logical_date] += 1
    prev_logical_date = curr_info.logical_date

The prev_logical_date and curr_info.logical_date are both set to timezone.utcnow() at consecutive loop iterations. This is why curr_info.logical_date <= prev_logical_date never fails and curr_info.logical_date.year != year waits for the end of the year.

What you think should happen instead?

I'm not sure, what is the best way to solve this:

1. Check if dag.timetable is ContinuousTimetable
2. Limit the number of iterations
3. Check that the diff between curr_info.logical_date and prev_logical_date is at least some amount - 1 minute or so.

How to reproduce

Make @continuous DAG and check the calendar view.

Operating System

Versions of Apache Airflow Providers

No response

Deployment

Other

Deployment details

No response

Anything else?

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[tanelk]

On a related note, the incrementing line in the snipet should be: dates[curr_info.logical_date.date()] += 1

[eladkal]

cc @bbovenzi worth checking with the new calendar view

[bbovenzi]

On a related note, the incrementing line in the snipet should be: dates[curr_info.logical_date.date()] += 1

Oh yeah, I caught that one when working on the new calendar view.
Let me also add a fix for continuous schedules