@Marvin i have a flow with thousands of tasks. I expect many of these tasks to fail --- and i'd like to show them as failed on the UI. it looks like when enough tasks fail, the whole flow fails and prefect stops running tasks. is this true, or is there potentially an issue w/ my flow specifically ?

✅ thought for 95.4 seconds

it depends entirely on how you do or do not handle failure. there's no inherent failure threshold after which we'd stop running tasks

Based on the research, I can tell you that Prefect should NOT automatically stop executing tasks just because many tasks have failed. Each task's execution is independent by default, and there's no built-in mechanism that stops flow execution after X number of failures. If you're seeing the entire flow stop when multiple tasks fail, this suggests there might be something specific in your flow's implementation causing this behavior. Here are a few things to check: 1. Task Dependencies: Are your tasks dependent on each other? If Task B depends on Task A and Task A fails, then Task B won't run. This could create a cascade effect. 2. Exception Handling: Are you properly handling exceptions in your tasks? Without proper exception handling, an error might propagate up and cause the flow to fail. 3. Resource Constraints: With thousands of tasks, are you potentially hitting any resource limits (memory, connections, etc.) that might cause the flow to fail? Could you share a simplified version of your flow structure or how you're defining these tasks? That would help identify if there's a specific implementation detail causing this behavior. Also, if you want tasks to show as failed in the UI but continue flow execution, you have a few options: 1. Wrap task logic in try/except blocks and handle failures gracefully 2. Use the

return_state=True

parameter when calling tasks to handle their states explicitly 3. Configure retry policies for tasks that you expect might fail Here's a simple example of handling expected failures:

python
from prefect import flow, task

@task
def task_that_might_fail():
    try:
        # Your potentially failing logic here
        raise ValueError("Expected failure")
    except Exception as e:
        print(f"Task failed as expected: {e}")
        # The task will be marked as failed but won't stop the flow
        raise

@flow
def my_flow():
    # This will show as failed in the UI but won't stop other tasks
    task_that_might_fail()
    # Other tasks will continue...

Would you like me to provide more specific guidance based on your flow's structure or implementation?

ok so i guess it's a problem on my side of the equation