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alex

02/17/2023, 10:37 PM
Question regarding result persistence and restarting failed flows: I have a flow that resembles this that I am running locally and on kubernetes
@flow
def demo_flow(x=1):
    val = task_1(x)
    val = task_2(val)
    val = task_3(val)
    val = task_4(val)
    val = prone_to_fail_task(val)
    return val
If expensive_prone_to_fail_task fails, I want to be able to restart my flow and have it retry just
prone_to_fail_task
again. What do I need to achieve that? Will adding
cache_key_fn=task_input_hash,
to just
task_4
be sufficient?
I'm getting this error currently when trying to restart from the UI
raise MissingResult(
prefect.exceptions.MissingResult: State data is missing. Typically, this occurs when result persistence is disabled and the state has been retrieved from the API.)
m

Marwan Sarieddine

02/17/2023, 11:22 PM
I think you need to configure your result storage appropriately See the relevant docs page here https://docs.prefect.io/concepts/results/#result-storage-location