@Marvin how to async on_running

It appears that the search results did not directly address the topic of using

async

with an

on_running

function in Prefect. However, I'll provide a general explanation and context on how you might achieve this in both Prefect 2.x and Prefect 3.x based on common practices and understanding of the framework. ### Prefect 2.x and Prefect 3.x Background

on_running

is typically used to define callback functions that execute when a task or flow state changes to running. Using

async

functions involves specifying async behavior within these callback functions. Since the documentation specifics were not retrieved, let's explore the concept and provide a basic idea of how you can structure this. ### General Approach in Prefect To utilize async functions within Prefect, you generally have to make use of the following: 1. Async/Await: Ensuring your function is defined with

async

and uses

await

for async operations. 2. AsyncIO Loop: Prefect should manage the event loop for running async functions. ### Example Implementation Here is a basic example of how you could define an

async

function to be used with the

on_running

callback in both Prefect 2.x and 3.x: #### Prefect 2.x Example

python
from prefect import task, Flow
import asyncio

@task
async def async_task():
    # Simulate async operation
    await asyncio.sleep(1)
    print("Async task complete")

@task
def task_on_running():
    async def on_running(flow_state, task_state):
        # Async operation when task starts running
        await async_task().run()
    
    return on_running

with Flow("example_flow", state_handlers=[task_on_running.run]) as flow:
    async_task()

flow.run()

#### Prefect 3.x Example

python
from prefect import flow, task
import asyncio

@task
async def async_task():
    await asyncio.sleep(1)
    print("Async task complete")

async def on_running(flow_state, task_state):
    await async_task()

@flow(name="example_flow", on_running=on_running)
async def main_flow():
    await async_task()

main_flow()

### Additional Considerations 1. Validation: Ensure all async operations are properly awaited. 2. Compatibility: Ensure your Prefect version supports async/await syntax as used. 3. Execution Environment: Confirm your runtime environment can handle async i.e., event loops, etc. For definitive details, I encourage reviewing the specific Prefect 2.x and 3.x documentation once available for your use case on their official site or the version-specific API references: - Prefect 2.x Documentation: https://docs-2.prefect.io/latest/ - Prefect 3.x Documentation: https://docs-3.prefect.io/ Feel free to adjust this template according to your exact Prefect version and the environment in which you are executing your flows and tasks.