Hello, I am starting using prefect, I am a luigi user so I am testing the “Result/Checkpoint/target” feature in prefect.. I tried the simple ex.

import prefect
from prefect import task, Flow, Parameter
from prefect.engine.results import LocalResult

result = LocalResult(dir="./prefect-results", )

@task
def hello_task(named_params):
    logger = prefect.context.get("logger")
    <http://logger.info|logger.info>(named_params)
    return 'asd'

with Flow("hello-flow", result=result) as flow:
    named_params = Parameter("named_params",)
    hello_task(named_params)

flow.run(named_params='param')

I was expecting to find a file in the the

./prefect-results

folder.. the folder is there but it is empty.. I also tried

import prefect
from prefect import task, Flow, Parameter
from prefect.engine.results import LocalResult

@task(checkpoint=True, result=LocalResult(dir="./prefect-results"))
def hello_task(named_params):
    logger = prefect.context.get("logger")
    <http://logger.info|logger.info>(named_params)
    return 'asd'

with Flow("hello-flow", ) as flow:
    named_params = Parameter("named_params",)
    hello_task(named_params)

flow.run(named_params='param')

also empty.. Am I doing something wrong, or I misunderstood how this feature work?

Did you also set checkpoint globally

export PREFECT__FLOWS__CHECKPOINTING=true

? as mentioned here: https://docs.prefect.io/core/advanced_tutorials/using-results.html#setting-up-to-handle-results

with the env variable it worked.. but even passing the

checkpoint=True,

parameter I need to have this?

Hello Rafael! You can see in the doc, which Abhishek pointed to 🙏, that:

For Core-only users, you must:

Opt-in to checkpointing globally by setting the prefect.config.flows.checkpointing to "True"

which is equivalent to

export PREFECT__FLOWS__CHECKPOINTING=true

, but if you run your flow with backend (Prefect Server or Prefect Cloud, and you use

flow.register

instead of

flow.run

Checkpointing will automatically be turned on

i got it.. thx a lot