TaskInstance State Change Events - on_task_instance_success not triggered when marking a task instance as success from the Airflow UI

[martenbloch]

Hi,

I created airflow listener(Airflow 3.1.3) that implements on_task_instance_success. I see that this event is not triggered when I mark a task instance as success from the Airflow UI(see attachment). According to the documentation: https://airflow.apache.org/docs/apache-airflow/stable/administration-and-deployment/listeners.html it should be possible.

For sure listener is implemented correctly, that is if I run a task that finish with success I see that on_task_instance_success is executed(added simple print - visible in task log). Problem shows up when task fails and then from UI I want to mark it as success - I do not see my log. I also checked scheduler and worker logs to be sure that my log did not go some other path.

For tests I used airflow docker compose.

Thanks in advance for any response.

[potiuk]

I would check if it is is not working in the upcoming 3.1.6 )watch devlist annoucement for rc candidate soon). Note however that the listeners are run possibly in different component than you think so you should check logs of all components. It's likely not visible in task_log if you just print it there.

If it does not work - open an issue and share your evidences.

[martenbloch]

Problem solved. It turns out that when you mark task as success via GUI, log is present in api-server. Key was your statement: "listeners are run possibly in different component than you think", thanks. Btw, I noticed that previous_state argument in function on_task_instance_success is always None(made test were task fails and then I marked it as success and then as fail).