Good evening, I ran into the following problem, wh...
# prefect-communityb
bral
08/17/2020, 10:36 PMGood evening, I ran into the following problem, which I find it difficult to solve. My flow looks something like this: And here's an example: I am using localagent, and this flow will be executed sequentially for each file. What is the correct way to parallelize it? Use multiprocessing? I am more inclined to use the dask executor, I looked at several examples, but nowhere the flow was registered, but simply executed. What is the best solution to parallelize the calculations (the best option, I assume, that each node of the executor takes a separate file for itself)?
bral
08/17/2020, 10:37 PMfrom prefect import task, Flow, case
@task
def is_running():
return False
def get_files():
return ['1','2','3','4']
@task
def read_file(file):
print(file)
return True
@task
def preprocess_file(file):
print(file)
return True
@task
def save_file(file):
print(file)
return True
with Flow("process") as flow:
condition = is_running()
with case(condition, False) as cond:
files = get_files()
for file in files[03]
r = read_file(file)
p = preprocess_file(file)
s = save_file(file)
r.set_downstream(p)
p.set_downstream(s)
flow.register("test")
k
Kyle Moon-Wright
08/17/2020, 10:48 PMHey @bral,
I think the best way to parallelize your flow for your use case would be your inclination to use the
DaskExecutorDaskExecutorLocalEnvironment Copy code
from prefect import Flow
from prefect.environments import LocalEnvironment
from prefect.engine.executors import DaskExecutor
environment = LocalEnvironment(executor=DaskExecutor())
flow = Flow(
"Dask Executor Example",
environment=environment
)
flow.register(project_name="project_name")Kyle Moon-Wright
08/17/2020, 10:49 PMAs far as parallelizing your tasks in a flow context, I'd recommend checking out the dependency structure in this idiom on parallelism within a Prefect Flow.
b
bral
08/17/2020, 11:01 PM@Kyle Moon-Wright i got it, thank you !
👍 2