Clarification on ExternalTaskMarker Behavior and Recursive Clearing in Airflow 3.0

[sharankow]

Hello,

We rely on ExternalTaskMarker to automatically clear tasks in downstream pipelines when an upstream task is cleared. So when the parent task is cleared, the child task for the same logical date will also be cleared, when "recursive" is selected during the clearing.

However, in most cases, we'd just like to clear the current DAG and not clear the downstream. A few challenges we've encountered:

• Clearing a DAG run, always triggers downstream and and there's no configurable way to limit clearing to only the current DAG.
• When clearing a task instance, the recursive option is selected by default, requiring users to manually uncheck it to avoid unintentionally clearing downstream tasks.

It'd be very useful to have the recursive button unchecked by default, so that users can opt-in when needed and downstream pipelines are only cleared when users explicitly intend to do so. This eliminates the risk of accidental clearing and ensures that downstream tasks are only cleared with conscious action. (#32574)

That said, while looking at the Airflow 3.0 UI updates, I noticed that clear task UI for 3.0 no longer includes the "recursive" button. I'm curious to know what this means for the ExternalTaskMarker going forward. Could someone clarify if ExternalTaskMarker will still work the same way in Airflow 3.0?