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Ron Van Buskirk

06/08/2020, 6:46 PM
Hello everyone -- I was trying to find out why a flow I was running paused for over a day and would welcome any troubleshooting suggestions 🙂 I had started a long-running flow with Prefect Core running from an Anaconda prompt on Windows 10. It runs on an AWS VM and basically calls stored procedures on a Postgres RDS database. I kicked it off processing Task A on Thursday saw that it had reached Task B by Friday. It completed Task B on Saturday at 5:22 am and then just hung afterwards. When I looked on Monday AM I saw that the backend had finished Task B but nothing was happening in the terminal. So I went to cancel the flow with a Ctrl-C. But as soon as I did that, it started running Task C after sitting idle for over a day? Here's a snippet from the flow output:
...
[2020-06-05 15:50:12,454] INFO - prefect.TaskRunner | Task 'task a': Starting task run...
[2020-06-05 17:15:04,576] INFO - prefect.TaskRunner | Task 'task a': finished task run for task with final state: 'Success'
[2020-06-05 17:15:04,576] INFO - prefect.TaskRunner | Task 'task b': Starting task run...
[2020-06-06 05:22:27,199] INFO - prefect.TaskRunner | Task 'task b': finished task run for task with final state: 'Success'
[2020-06-08 14:23:12,015] INFO - prefect.TaskRunner | Task 'task c': Starting task run...
Is there anything that I could have accidentally entered in the terminal that would have put it into some type of 'wait' state? Or any other suggestions about things I could check?
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nicholas

06/08/2020, 7:00 PM
Hi @Ron Van Buskirk - I could be wrong here but I think this is something specific to Windows machines and CP. If that's indeed the case, unfortunately I'm not sure there's a fix from the Prefect Core end because this has been a Windows bug for many (maybe 20?) years. (here, here, and here are some examples)
👀 1
a

Avi A

06/08/2020, 7:02 PM
Running the agent with the flags
-vf
will give a more verbose output, and show output from the tasks themselves. For me it really helped in debugging issues where the tasks wouldn’t report their status to the core server for various reasons
:upvote: 1
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Ron Van Buskirk

06/08/2020, 7:30 PM
@nicholas Thx!! that seems to describe the problem exactly 🙄 Will avoid running from Windows or maybe just switch to the GUI from now on 👍
:upvote: 1
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nicholas

06/08/2020, 7:31 PM
Glad to help!
r

Ron Van Buskirk

06/08/2020, 7:33 PM
@Avi A I didn't know about the
-vf
flags. Good to know, and will try that in future troubleshooting 👍