Sean Conroy05/25/2023, 11:35 PM
What is the limit? How can I solve this?
Failed("Flow run encountered an exception. PrefectHTTPStatusError: Client error '429 Too Many Requests'"
Marvin05/25/2023, 11:37 PM
Sean Conroy05/25/2023, 11:38 PM
Marvin05/25/2023, 11:40 PM
parameter of the
class. A semaphore is a synchronization primitive that can be used to limit the number of concurrent tasks running at the same time. Here's an example of how to use a semaphore to limit concurrency:
In this example, the
python from prefect import Flow, task from prefect.executors import LocalExecutor from prefect.schedules import IntervalSchedule from prefect.triggers import any_successful from prefect.utilities.tasks import Semaphore # Create a semaphore with a concurrency limit of 2 semaphore = Semaphore(max_concurrent=2) @task def task_a(): print("Task A") @task def task_b(): print("Task B") @task def task_c(): print("Task C") with Flow("concurrency_example") as flow: a = task_a() b = task_b() c = task_c() # Acquire the semaphore before running the tasks semaphore.acquire(a) semaphore.acquire(b) semaphore.acquire(c) # Release the semaphore after the tasks are completed semaphore.release(a) semaphore.release(b) semaphore.release(c) # Run the flow flow.run(executor=LocalExecutor())
class is used to limit the concurrency of tasks A, B, and C to a maximum of 2 concurrent tasks. The tasks will acquire the semaphore before running and release it after completion. Remember, it's not the size of your semaphore that matters; it's how you use it.
Sean Conroy05/25/2023, 11:42 PM
Marvin05/25/2023, 11:42 PM
details here (https://docs.prefect.io/latest/concepts/tasks/?h=concu#cli) you can check out the work queue level concurrency rate limit docs (https://docs.prefect.io/latest/concepts/work-pools/?h=concurrency#work-pool-concurrency) or task-level concurrency here (https://docs.prefect.io/latest/concepts/tasks/?h=concurr#task-run-concurrency-limits)
prefect concurrency-limit [command] [arguments]
Nate05/26/2023, 1:48 AM
Anthony Head05/26/2023, 2:05 AM