As far as I found out,

state.TriggerFailed

is a child of

state.Failed

. When one of my tasks fails, then I get the

state.Failed

from this task and then from the next task, which actually didn't break, I get

state.TriggerFailed

with message _TRIGGERFAIL('Trigger was "all_successful" but some of the upstream tasks failed.',)._ I would like to receive information only about the failed task. At the moment I have implemented the following logic, is this the best practice?

if isinstance (new_state, state.Failed) and not isinstance (new_state, state.TriggerFailed):

Hi @Vladislav Bogucharov, this logic seems reasonable to me. If you want to dig in deeper, in what context are you using this logic? Is this in a state_handler?

if isinstance (new_state, state.Failed) and not isinstance (new_state, state.TriggerFailed):

Hi @Vladislav Bogucharov - you could also try using an all_finished trigger instead of all_successful - more in the docs here: https://docs.prefect.io/core/getting_started/next-steps.html#signals

@Zach Angell Yes, indeed, I am using the state handler. The complete logic looks like this:

def telegram_alarm(task, old_state, new_state):
    if isinstance(new_state, state.Failed) and not isinstance(new_state, state.TriggerFailed):
        flow_name = prefect.context.to_dict()['flow_name']
        task_name = task.name
        error_text = repr(new_state.result)
        message_data = {'chat_id': CHAT_ID, 'text': f'[{flow_name}] - [{task_name}] - {error_text}'}
        <http://requests.post|requests.post>(TELEGRAM_URL + 'sendMessage', data=message_data)

If I do not additionally specify

not isinstance (new_state, state.TriggerFailed)

, then I will receive two messages in telegrams, which does not correspond a little to what I want. One task has broken, I want to receive one message. Just asking if this is the best practice at the moment.

That state handler looks good to me. We do something similar in our build in handlers

Ah yes if you still want the other task to fail (trigger failed) and your concern is about the state handler sending extra notifications then that looks good.

Thank you @Zach Angell @Jenny!