hi, is there a way to kill task in flow context? I know how to start a task in there, fairly easy. But not to kill a started one.

You can

raise ENDRUN

. This will avoid any retries. Docs . Is this what you meant?

not really. For example, if I have a task A, inside of it, it’s calling another task B. But when I cancel the flow, the task A is cancelled. but task B is still running on background. I want a command to kill task B at task A’s finally statement.

You mean task A calls something like

RunNamespacedJob

that spins up new compute like this:

@task
def task_a():
    RunNamespacedJob().run()
    return

In this case,

RunNamespacedJob

is not a real task and in general, Prefect is currently not able to close hardware through cancelletation

yes that is right^

Yeah in this case, there is no way I think. Cancelling

task_a

mid flow run through the flow is very hard. Because it must have already executed by the time downstream tasks are reached

if I can get some metadata from

RunNamespacedJob().run()

like task_id, I can call something like

client.set_task_run_state()

Ah then in that case, you can’t get metadata from

RunNamespacedJob

from a downstream task unless you persist it in some location that can be retrieved from downstream. If you are getting the metadata in the same task,you would need a modified task that allows you to poll the NamespacedJob or something or check the logs, and then you can have a conditional that

raise SUCCESS

or

raise FAIL

. These would be better than the

client.set_task_run_state()

if the logic is in the same task.

I see. Yeah I need to take a different approach. Thanks @Kevin Kho ! Have a good weekend.