How to restart a failed task on Airflow

In the UI:

1. Go to the dag, and dag run of the run you want to change
2. Click on GraphView
3. Click on task A
4. Click “Clear”

This will let task A run again, and if it succeeds, task C should run.
This works because when you clear a task’s status, the scheduler will treat it as if it hadn’t run before for this dag run.