DAG scheduling broke after the time change (29/10/2022) and hasnt worked since

Question

I am running a couple of DAGs via airflow which used to run fine until the 29th of October, when the time changed and ever since then they haven't run at all.

The DAGs are scheduled to run every Monday at 6am and below is the code:

default_args = {
        'owner': 'airflow',
        'start_date': dt.datetime(year=2022, month=10, day=17),#, hour=10),
        'concurrency': 1,
        'retries': 5,
        'retry_delay': dt.timedelta(seconds=10)

}
bucket_name = "store_order_forecast_s1_2_3"
dag = DAG(
    dag_id=bucket_name,
    default_args=default_args,
    schedule_interval='0 6 * * 1',
    catchup=False
)

The server is correctly identifying the next run time, but it always skips it.

enter image description here

Has anyone run in the same issue?

Thank you in advance

I have tried changing the run date and reset the DAG but it didnt work.

Answer 1

Has anything else changed in your DAG code around that time? DAGs should be scheduled on UTC so I would not expect the change between summer and wintertime to have an influence on the DAG schedule itself.

Your concurrency setting being 1 could be the issue. This means only one task instance can ever be active across all task instances of this DAG: maybe a task got stuck in a running state last October and this is preventing new tasks to be scheduled? I would check in your Airflow UI -> Browse -> Task Instances if old task instances of that DAG are still running (or try setting the concurrency parameter to a higher value, the default value is 16).