When the airflow webserver shows up errors like Broken DAG: [<path/to/dag>] <error>, how and where can we find the full stacktrace for these exceptions?
I tried these locations:
/var/log/airflow/webserver -- had no logs in the timeframe of execution, other logs were in binary and decoding with strings gave no useful information.
/var/log/airflow/scheduler -- had some logs but were in binary form, tried to read them and looked to be mostly sqlalchemy logs probably for airflow's database.
/var/log/airflow/worker -- shows up the logs for running DAGs, (same as the ones you see on the airflow page)
and then also under /var/log/airflow/rotated -- couldn't find the stacktrace I was looking for.
I am using airflow v1.7.1.3
Usually I used the command airflow list_dags which print the full stacktrace for python error found in dags.
That will work with almost any airflow command as airflow parse dags folder each time you use a airflow CLI command.
If you want to compile and see any syntax error, you can also try python your_dag.py
What you want to do is access the inner logs of the webserver so that you get the full stacktrace. My Airflow server is being executed in a Docker image so I'll use Docker to fetch these logs but the idea remains.
docker ps- fetch the PID of the webserver
docker logs [PID]- read the full logs of the given Airflow webserver.
This should contain the exact information of why your DAG build failed.
来源：https://stackoverflow.com/questions/43944741/debugging-broken-dags