@Marvin I am running many task concurrently via ConcurrentTaskRunner. Sometimes I feel that one specific task is struck without any logs. So I would like to cancel that particular task. How can I achieve this ?? Can I terminate the task based knowledge filename in CLI ?

To cancel a specific task in Prefect when using a ConcurrentTaskRunner, you'll need to take a few steps using Prefect's orchestration and CLI capabilities. ### Node Details for Cancelling Tasks: 1. Prefect Documentation on Canceling Tasks: To cancel a task, you generally need to identify the task by its

task_run_id

. Here are some checkpoints: - Cancellation is robust but may face issues if the infrastructure block for the flow run is removed. - If the task is in the

Submitted

state, you may halt its execution, but issues can prevent perfect enforcement. 2. Prefect GitHub Issues: The community has raised related issues about tasks hanging, especially with async tasks (

jaydebeapi

), causing the Python process to stall until it's manually killed. This might be related to your issue of a task being stuck without logs. ### Steps to Terminate a Task: 1. Identify the Task's

task_run_id

: - You can use

prefect

CLI or the Prefect UI to locate the

task_run_id

. 2. Use the Prefect CLI to Cancel the Task: - Once you have the

task_run_id

, you can terminate the task using the CLI:

shell
     prefect task-run cancel <task_run_id>

### Examples: #### In Python: You might want to create a small script to cancel a task dynamically using the Prefect client:

python
from prefect.client import get_client

async def cancel_task_run(task_run_id: str):
    async with get_client() as client:
        await client.update_task_run(task_run_id, state="Cancelled")

# Example usage
import asyncio
task_run_id = "your-task-run-id"
asyncio.run(cancel_task_run(task_run_id))

#### CLI (Command-Line Interface): Directly from your terminal:

shell
prefect task-run cancel <your-task-run-id>

### Further Information: - Prefect Documentation on Task Runners: Link - Prefect Blog on Deploying Task Queues: Link - GitHub Issues related to task hang: Issues If you need more granular control or further examples, you can refer to the Prefect documentation or GitHub discussions linked above. This should guide you on effectively terminating a hanging task.

@Marvin prefect task-run cancel <task id> throws no such command called ‘cancel’ … What should I do ??

It looks like the command to use in the Prefect CLI to cancel a task run is cancel flow run, rather than the mistaken

prefect task-run cancel

command. Instead, you'll want to cancel the flow run that contains the stuck task. Just ensure that you have Prefect's experimental features enabled and use the CLI or Python client accordingly. ### Steps to Cancel a Flow Run via CLI: 1. Enable Enhanced Cancellation (Optional):

bash
   prefect config set PREFECT_EXPERIMENTAL_ENABLE_ENHANCED_CANCELLATION=True

2. Cancel the Flow Run: You need the

flow_run_id

for the flow containing the task. Once you have it:

bash
   prefect flow-run cancel <flow_run_id>

### Example for Prefect CLI:

bash
prefect flow-run cancel <your-flow-run-id>

### Using Prefect Python Client:

python
from prefect.client import get_client

async def cancel_flow_run(flow_run_id: str):
    async with get_client() as client:
        await client.update_flow_run(flow_run_id, state="Cancelled")

# Example usage
import asyncio
flow_run_id = "your-flow-run-id"
asyncio.run(cancel_flow_run(flow_run_id))

### Reference: - Prefect Flows Documentation: Link - Prefect AWS Integration: Link If you need further assistance, Prefect's Slack and GitHub channels can provide community support, as cancellation implementations may evolve with new updates.