(ImportError: No module named 'MySQLdb') celery executor issue

[Shrashti]

Hi,

I am facing below issue while running DAGS using airflow backfill <DAG_id> -s <start_date> -e <end_date>

Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/airflow/executors/celery_executor.py", line 94, in sync
state = task.state
File "/usr/local/lib/python3.5/dist-packages/celery/result.py", line 431, in state
return self._get_task_meta()['status']
File "/usr/local/lib/python3.5/dist-packages/celery/result.py", line 370, in _get_task_meta
return self._maybe_set_cache(self.backend.get_task_meta(self.id))
File "/usr/local/lib/python3.5/dist-packages/celery/backends/base.py", line 352, in get_task_meta
meta = self._get_task_meta_for(task_id)
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/init.py", line 53, in _inner
return fun(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/init.py", line 122, in _get_task_meta_for
session = self.ResultSession()
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/init.py", line 99, in ResultSession
**self.engine_options)
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/session.py", line 58, in session_factory
engine, session = self.create_session(dburi, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/session.py", line 44, in create_session
engine = self.get_engine(dburi, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/celery/backends/database/session.py", line 41, in get_engine
return create_engine(dburi, poolclass=NullPool)
File "/usr/local/lib/python3.5/dist-packages/sqlalchemy/engine/init.py", line 391, in create_engine
return strategy.create(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/sqlalchemy/engine/strategies.py", line 80, in create
dbapi = dialect_cls.dbapi(**dbapi_args)
File "/usr/local/lib/python3.5/dist-packages/sqlalchemy/dialects/mysql/mysqldb.py", line 110, in dbapi
return import('MySQLdb')
ImportError: No module named 'MySQLdb'

[celestialorb]

Same issue here. It feels like SqlAlchemy is defaulting to MySQL instead of Postgres.

[shao-shuai]

try pip install mysql-connector-python
and pip install mysql