@Marvin, how to call a task with a specific timeout at runtime?

To set a timeout for a task at runtime in Prefect 3.x, you can utilize the

timeout

utility. This utility helps in enforcing a timeout on the execution of a task. If the task execution exceeds the specified timeout duration, a

TaskRunTimeoutError

will be raised. Here's a concise example of how you might implement this:

python
from prefect import task, flow
from prefect.utilities.timeout import timeout

@task
def my_task():
    # Your task logic here
    pass

@flow
def my_flow():
    with timeout(seconds=10):
        my_task()

my_flow()

In this example, the

timeout

context manager is used to enforce a 10-second timeout on

my_task

. If

my_task

exceeds this duration, it will be interrupted, and a

TaskRunTimeoutError

will be raised. For more details, you can refer to the Prefect 3.x documentation on writing tasks. Do note that the concept of agents has been replaced by workers in Prefect 3.x, and work pools replace the infra blocks from

prefect.infrastructure

. Ensure that your environment is set up accordingly.

@Marvin, how can I call a async task with a specific timeout?

To call an asynchronous task with a specific timeout in Prefect 3.x, you can use the

timeout_async

utility. This utility is designed to handle timeouts specifically for asynchronous contexts. Here's an example of how you might implement this:

python
from prefect import task, flow
from prefect.utilities.timeout import timeout_async

@task
async def my_async_task():
    # Your async task logic here
    pass

@flow
async def my_async_flow():
    async with timeout_async(seconds=10):
        await my_async_task()

await my_async_flow()

In this example, the

timeout_async

context manager is used to enforce a 10-second timeout on

my_async_task

. If the task execution exceeds this duration, it will be interrupted, and a timeout exception will be raised. For more details, you can refer to the Prefect 3.x documentation on writing tasks.

@Marvin, how can I call an async task.submit with a specific timeout at runtime?

To call an asynchronous task using

.submit

with a specific timeout in Prefect 3.x, you can use the

timeout_async

utility within your task or flow. The

submit

method allows you to execute tasks asynchronously, and you can handle the timeout within the task execution itself. Here's a conceptual example of how you might implement this:

python
from prefect import task, flow
from prefect.utilities.timeout import timeout_async

@task
async def my_async_task():
    # Your async task logic here
    pass

@flow
async def my_async_flow():
    future = my_async_task.submit()

    # Use timeout_async to handle the timeout for the task execution
    async with timeout_async(seconds=10):
        await future.result()

await my_async_flow()

In this example,

my_async_task.submit()

submits the task for asynchronous execution, and

timeout_async

is used to enforce a 10-second timeout on the task's completion. If the task execution exceeds this duration, it will be interrupted. For more details on using task runners and futures, you can refer to the Prefect 3.x documentation on task runners.

@Marvin, I can I catch a timeout_async exception?

To catch a

timeout_async

exception in Prefect 3.x, you can use a try-except block within your asynchronous flow or task. The

timeout_async

utility raises a

TimeoutError

when the specified duration is exceeded. Here's how you can handle it:

python
from prefect import task, flow
from prefect.utilities.timeout import timeout_async

@task
async def my_async_task():
    # Your async task logic here
    pass

@flow
async def my_async_flow():
    try:
        async with timeout_async(seconds=10):
            await my_async_task()
    except TimeoutError as exc:
        # Handle the timeout exception
        print(f"Task failed due to timeout: {exc}")

await my_async_flow()

In this example, if

my_async_task

exceeds the 10-second limit, the

TimeoutError

is caught in the except block, allowing you to handle the timeout gracefully.

@Marvin, how can I call an async task.submit with a specific timeout at runtime and cancel the task if an exception is raised?

To call an async task using

.submit

with a specific timeout and cancel the task if a timeout exception is raised in Prefect 3.x, you can use the

timeout_async

utility along with the

cancel

method on the future returned by

submit

. Here's how you can do it:

python
from prefect import task, flow
from prefect.utilities.timeout import timeout_async
from prefect.futures import PrefectFuture

@task
async def my_async_task():
    # Your async task logic here
    pass

@flow
async def my_async_flow():
    future: PrefectFuture = my_async_task.submit()

    try:
        async with timeout_async(seconds=10):
            await future.result()
    except TimeoutError as exc:
        print(f"Task failed due to timeout: {exc}")
        future.cancel()  # Cancel the task if a timeout occurs

await my_async_flow()

In this example,

my_async_task.submit()

submits the task for asynchronous execution. The

timeout_async

utility enforces a 10-second timeout. If the task does not complete within this time, a

TimeoutError

is raised, which you can catch and handle by calling

future.cancel()

to cancel the task.

@Marvin, how can I call an async task.submit with a specific timeout at runtime and cancel the task if an exception is raised in prefect 2.x?

In Prefect 2.x, to call an async task using

.submit

with a specific timeout and cancel the task if an exception is raised, you can use the

timeout_seconds

parameter in the task definition. Unfortunately, the direct cancellation of tasks is not as straightforward as in Prefect 3.x, but you can manage exceptions and timeouts at the flow level. Here's how you can set a timeout and handle exceptions:

python
from prefect import task, flow
import asyncio

@task(timeout_seconds=10)
async def my_async_task():
    # Your async task logic here
    await asyncio.sleep(15)  # Simulate a long-running task

@flow
async def my_async_flow():
    try:
        await my_async_task.submit()
    except Exception as exc:
        print(f"Task failed due to an exception: {exc}")
        # Handle task cancellation logic here if necessary

asyncio.run(my_async_flow())

In this example, the

timeout_seconds

parameter is used to specify a timeout for

my_async_task

. If the task exceeds this duration, a timeout exception is raised. You can catch this exception in the flow and implement any necessary cancellation logic. However, Prefect 2.x does not provide a built-in method to cancel tasks programmatically; you may need to handle such logic externally or at the flow level. For more details on task execution and handling in Prefect 2.x, refer to the Prefect 2.x task concepts.