We've seen this before as well, it's a bug in the Celery Executor that has a bunch of different manifestations.
There is at least one open issue relating to this bug: https://issues.apache.org/jira/browse/AIRFLOW-1463 I have been working on a fix but it's likely to be a few more days before I have a chance to make some progress. --George On Fri, Jul 28, 2017 at 5:05 PM David Capwell <dcapw...@gmail.com> wrote: > We noticed that in the past few days we keep seeing tasks stay in the > queued state. Looking into celery, we see that the task had failed. > > Traceback (most recent call last): > File "/python/lib/python2.7/site-packages/celery/app/trace.py", line > 367, in trace_task > R = retval = fun(*args, **kwargs) > File "/python/lib/python2.7/site-packages/celery/app/trace.py", line > 622, in __protected_call__ > return self.run(*args, **kwargs) > File > "/python/lib/python2.7/site-packages/airflow/executors/celery_executor.py", > line 59, in execute_command > raise AirflowException('Celery command failed') > AirflowException: Celery command failed > > > Why does airflow not learn about this and recover? And what can we do to > prevent this? > > Thanks for your time reading this email. >