Starting Airflow webserver fails with sqlalchemy.exc.NoInspectionAvailable: No inspection system is available

38
votes

Installation done properly. db initiated properly and trying to start the webserver shows the following error.

I reinstalled everything but its still not working.

I will appreciate if anyone help me.

Console output:

$:~/airflow# airflow webserver -p 8080
  ____________       _____________
 ____    |__( )_________  __/__  /________      __
____  /| |_  /__  ___/_  /_ __  /_  __ \_ | /| / /
___  ___ |  / _  /   _  __/ _  / / /_/ /_ |/ |/ /
 _/_/  |_/_/  /_/    /_/    /_/  \____/____/|__/
[2020-04-08 13:14:20,573] {__init__.py:51} INFO - Using executor SequentialExecutor
[2020-04-08 13:14:20,574] {dagbag.py:403} INFO - Filling up the DagBag from /home/cato_service/airflow/dags
Traceback (most recent call last):
  File "/usr/local/bin/airflow", line 37, in <module>
    args.func(args)
  File "/usr/local/lib/python3.6/dist-packages/airflow/utils/cli.py", line 75, in wrapper
    return f(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/airflow/bin/cli.py", line 900, in webserver
    app = cached_app_rbac(None) if settings.RBAC else cached_app(None)
  File "/usr/local/lib/python3.6/dist-packages/airflow/www/app.py", line 233, in cached_app
    app = create_app(config, testing)
  File "/usr/local/lib/python3.6/dist-packages/airflow/www/app.py", line 103, in create_app
    models.Chart, Session, name="Charts", category="Data Profiling"))
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/view.py", line 330, in __init__
    menu_icon_value=menu_icon_value)
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/model/base.py", line 818, in __init__
    self._refresh_cache()
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/model/base.py", line 913, in _refresh_cache
    self._search_supported = self.init_search()
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/view.py", line 581, in init_search
    if tools.is_hybrid_property(self.model, name):
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/tools.py", line 209, in is_hybrid_property
    return last_name in get_hybrid_properties(last_model)
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/tools.py", line 190, in get_hybrid_properties
    for key, prop in inspect(model).all_orm_descriptors.items()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/inspection.py", line 72, in inspect
    "available for object of type %s" % type_
sqlalchemy.exc.NoInspectionAvailable: No inspection system is available for object of type <class 'method'>
3
airflow
Hey there and welcome to stackoverflow. I would recommend you read through stackoverflow.com/help/how-to-ask or take a look at some other questions to improve your future questions. For example: try to mark code or console output as code or preformatted text for easier readability. Also, instead of db initiated properly, it would probably help people in answering your question if you copied the exact command you ran. - Christopher Beck

3 Answers

57
votes

Just hit this myself. its an issue with SQLAlchemy dependency

to fix I did the following:

pip3 uninstall SQLAlchemy
pip3 install SQLAlchemy==1.3.15

https://github.com/apache/airflow/issues/8211

9
votes

Including the instruction pip install SQLAlchemy==1.3.15 in the Dockerfile and rebuilding the image has solved the issue. Thanks a lot @Java Guy!

0
votes

I faced the above issue. I added below line in Dockerfile

&& pip install SQLAlchemy==1.3.15 \

Build the docker image as

docker build --rm -t <tag> .

Run :

docker run -d -p 8080:8080 <tag>