[Question] Task duration keeps increasing for skipped tasks due to DAG timeout

[Szjs-z]

Hi Airflow community,

I've encountered an issue where task duration keeps increasing for tasks that are skipped due to DAG timeout:

Problem Description:
When a DAG run times out due to dagrun_timeout, the unfinished tasks are marked as SKIPPED. However, in the Web UI, the task duration continues to increase even though the task state is SKIPPED :

Root Cause Analysis:
From code inspection in airflow/jobs/scheduler_job.py, the _schedule_dag_run method handles DAG timeout by:

        if (
            dag_run.start_date
            and dag.dagrun_timeout
            and dag_run.start_date < timezone.utcnow() - dag.dagrun_timeout
        ):
            dag_run.set_state(DagRunState.FAILED)
            unfinished_task_instances = session.scalars(
                select(TI)
                .where(TI.dag_id == dag_run.dag_id)
                .where(TI.run_id == dag_run.run_id)
                .where(TI.state.in_(State.unfinished))
            )
            for task_instance in unfinished_task_instances:
                task_instance.state = TaskInstanceState.SKIPPED
                session.merge(task_instance)
            session.flush()
            self.log.info("Run %s of %s has timed-out", dag_run.run_id, dag_run.dag_id)

1. Setting DAG run state to FAILED
2. Marking unfinished tasks as SKIPPED
3. But it doesn't set end_date for these task instances

I'm wondering if this is a known issue or if there's a recommended way to handle this.

Thanks,
Chris Zhao