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<@ULVA73B9P> when a job fails, does it keep on run...
# ask-marvin
s
@Marvin when a job fails, does it keep on runnng?
m
Ah, the existential questions of a job's life. In the context of Prefect, a job (or task) that fails will not continue running. However, the behavior of the flow that the task is part of depends on how you've set up your error handling. If you've set up retries for the task, Prefect will attempt to run it again after a specified period of time. If you haven't, the task will be marked as failed and the flow run will end, unless you've set up your flow to handle failures in a specific way, such as using a 
catch
signal to perform some action when a task fails. Would you like more detailed information on this topic?
s
I do not have anything like that
@Marvin I do not have anything like that
@Marvin why is it keep running
m
In Prefect, you can handle task failures in a few ways: 1. Retries: You can set up retries for a task, which means Prefect will attempt to run it again after a specified period of time if it fails. You can even add jitter to the retry delays to prevent "thundering herds" while keeping the average retry delay time constant. Here's an example:
Copy code
from prefect import task
from prefect.tasks import exponential_backoff

@task(
  retries=3,
  retry_delay_seconds=exponential_backoff(backoff_factor=10),
  retry_jitter_factor=1,
)
def some_task_with_exponential_backoff_retries():
  ...
2. Catch Signal: You can also use a 
catch
signal to perform some action when a task fails. This is not covered in the excerpts I found, but it's a feature of Prefect that allows you to handle exceptions in a specific way. 3. Flow Behavior: If a task fails and you haven't set up retries or a catch signal, the task will be marked as failed and the flow run will end. However, you can design your flow to handle failures in a specific way, such as continuing with other tasks or ending the flow run immediately. For more detailed information, you can refer to the Prefect documentation on Flows and Tasks.
If a task in Prefect keeps running despite failing, there could be a few reasons: 1. Retries: Even if you haven't explicitly set up retries, Prefect tasks have a default retry count of 2 and a retry delay of 10 seconds. This means that if a task fails, Prefect will automatically try to run it again twice, with a 10-second pause between attempts. 2. State Handlers: If you've set up a state handler for your tasks or flow, it could be changing the state of the task upon failure, causing it to run again. 3. Task Dependencies: If the failed task has downstream tasks that are set to run regardless of their upstream task's state, those tasks will run, potentially giving the appearance that the failed task is still running. 4. Infrastructure Issues: If there's an issue with your infrastructure, such as a problem with your executor or agent, tasks might not be properly marked as failed and could continue running. Without more specific information about your flow and tasks, it's hard to say exactly why a failed task would continue running. If you're seeing this behavior and none of the above explanations apply, it might be a good idea to reach out to Prefect support or check the Prefect community for help.
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