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<@ULVA73B9P> I'm getting an OSError when running f...
# ask-marvin
a
@Marvin I'm getting an OSError when running flows inside a process worker on an EC2 machine. The flows themselves are completing successfully. Any idea what's going on here?
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An error occurred while monitoring flow run 'my-flow-run-id'. The flow run will not be marked as failed, but an issue may have occurred.
Traceback (most recent call last):
  File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/to_thread.py", line 33, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 877, in run_sync_in_worker_thread
    return await future
           ^^^^^^^^^^^^
  File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 807, in run
    result = context.run(func, *args)
             ^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 5] Input/output error
m
Your message was too long by 51 tokens - please shorten it and try again. For reference, here's your message at the allowed limit:
I'm getting an OSError when running flows inside a process worker on an EC2 machine. The flows themselves are completing successfully. Any idea what's going on here?
```An error occurred while monitoring flow run 'my-flow-run-id'. The flow run will not be marked as failed, but an issue may have occurred. Traceback (most recent call last): File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/prefect/utilities/processutils.py", line 314, in stream_text await sink.write(item) File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/_core/_fileio.py", line 119, in write return await to_thread.run_sync(self._fp.write, b) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/to_thread.py", line 33, in run_sync return await get_asynclib().run_sync_in_worker_thread( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/ec2-user/prefect_env/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 877, in run_sync_in_worker_thread return await future ^^^^^^^^^^^^ File "/home/ec2-user/prefect_env/lib/python3.12/site
Based on the information from both the GitHub issues and Prefect documentation, it seems your problem might be related to general issues with monitoring flow runs within certain environments or worker setups. Here are some specifics and potential solutions: ### GitHub Issue: Monitoring Issues with Workers - Similar Error: A 
prefect-azure
worker reported trouble monitoring flow runs, with a traceback involving 
anyio.to_thread.run_sync
and similar stack traces. The issue had to do with capturing logs. - Link: ACI Worker: An error occurred while monitoring flow run ### Prefect Documentation: General Troubleshooting - Related Troubleshooting Steps: This documentation includes several examples of common issues including unclosed socket connections which might hint towards resource release problems. - Link: Troubleshooting Guide ### Potential Issues & Solutions 1. Resource Handling: Ensure that all resources (like sockets, files, etc.) are properly closed after their use. This can be critical in resource-constrained environments like EC2. 2. Log Handling: Review your log handling setup. Excessive logging or improper setup can sometimes lead to I/O issues. 3. Worker Configuration: Depending on your task, switching to different worker types like 
EC2
if you're using containers can sometimes help: - AWS ECS Guide: ECS Worker Guide ### Further Steps - Updating and Debugging: - Ensure you're using the latest version of Prefect and any related libraries. - Review the worker setup and parameters to ensure they match your deployment environments needs.
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python
import prefect
from prefect import flow, task

@task
def example_task():
    print("Task executed")

@flow
def example_flow():
    example_task()

example_flow()
This simplified flow should help narrow down if the issue lies within the task definitions or resource handling during execution. Would you like more detailed guidance on specific parts, or some targeted code examples?
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