Apache Airflow version:

1.10.14

Environment:

Regular Airflow setup:
Python 3.6.2
Airflow 1.10.14
Celery 4.3.0

What happened:

max_active_runs isn't limiting DAG runs on DAGs when None schedule_interval (unsure about with a schedule, I don't use them). I set it to 20 but more than 20 are running.

It used to work on older versions of 1.10.

What you expected to happen:

DAG Runs to be limited to what I set in max_active_runs

Anything else we need to know:

I've had "max_active_runs" set as a DAG parameter for a long time and it always worked fine until this latest update I went from 1.10.12 -> 1.10.14.

I didn't see anything relevant in the upgrade changelogs, so I didn't realize it wasn't working until I look into some problems.

More so, the 0/20 doesn't seem to display in the RBAC UI, but that could be a change in the new UI since I just switched to that as well.