jedcunningham edited a comment on issue #18939:
URL: https://github.com/apache/airflow/issues/18939#issuecomment-953395944
I was able to reproduce this. The following traceback is the original
failure:
```
File
"/Users/jedc/github/airflow/airflow/migrations/versions/7b2661a43ba3_taskinstance_keyed_to_dagrun.py",
line 322, in upgrade
ondelete=ondelete,
...
sqlalchemy.exc.OperationalError: (MySQLdb._exceptions.OperationalError)
(3780, "Referencing column 'dag_id' and referenced column 'dag_id' in foreign
key constraint 'task_reschedule_ti_fkey' are incompatible.")
[SQL: ALTER TABLE task_reschedule ADD CONSTRAINT task_reschedule_ti_fkey
FOREIGN KEY(dag_id, task_id, run_id) REFERENCES task_instance (dag_id, task_id,
run_id) ON DELETE CASCADE]
```
Which is this section:
https://github.com/apache/airflow/blob/20847fdbf8ecd3be394d24d47ce151c26d018ea1/airflow/migrations/versions/7b2661a43ba3_taskinstance_keyed_to_dagrun.py#L303-L310
This fails because the column in `task_instance` and `task_reschedule`
differ:
```
# task_instance
`dag_id` varchar(250) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
# task_reschedule
`dag_id` varchar(250) NOT NULL,
```
The traceback in the description then happens on subsequent `airflow db
upgrade` runs.
The root cause is incorrect encoding/collation settings. If I follow the
documentation for using a [MySQL database with
Airflow](https://airflow.apache.org/docs/apache-airflow/stable/howto/set-up-database.html#setting-up-a-mysql-database),
everything is happy. If I use the defaults we run into this.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
