<@ULVA73B9P> Task run failed with exception: Value...
# ask-marvin
d
@Marvin Task run failed with exception: ValueError('Path /root/.prefect/storage/... does not exist.')
m
The issues you're encountering seem related to Prefect's handling of storage paths and potential race conditions when accessing serialized files. Here are some relevant points to consider: 1. Race Condition and File Access: - A ValueError occurs if a task attempts to access a file that hasn't been written yet. This can happen due to a race condition where tasks start before the necessary files are available. Source: GitHub Issue #6086 2. Multiple Agents Issue: - Running multiple agents on the same work queue can cause frequent crashes. This can be mitigated by using a single agent or setting
PREFECT_AGENT_PREFETCH_SECONDS
to 0 to reduce the likelihood of concurrent file access. Source: GitHub Issue #6725 3. Troubleshooting Tips: - Verify that the path exists and is accessible before attempting to use it in your task. - If using cloud storage, ensure the correct local paths are being set and that there’s proper synchronization. For more detailed guidance, you might want to explore the following links: - Task Execution and Errors: https://docs.prefect.io/latest/guides/troubleshooting/ - Dask Task Runner Integration: https://docs.prefect.io/latest/integrations/prefect-dask/task_runners/ - GCP Storage Integration: https://docs.prefect.io/latest/integrations/prefect-gcp/cloud_storage/ Make sure your configurations are correct and consider running a single agent initially to rule out concurrency issues.
n
hi @datamongus - this normally means • I ran a task with local result persistence (often on a container) • i ran that task again in a new place (usually a new container) and couldnt find the place the API said the result lived at normally its when you persist a result in one flow run container, the local (wrt that container) storage goes away with the container, but the API keeps that result path, thinking it will be available on the next container so if this is an accurate description, you can configure remote (blob) storage for result persistence
d
Ah thank you. Can you point me to an example of how I can do that for results ? And yes I did turn on default persist results to true
yep you can make a result storage block, using prefect_aws, prefect_gcp or azure, and then set that block as the
result_storage
kwarg in the decorator (at the flow level, so for all tasks, or on a task by task basis)
d
Thank you
I see the example uses S3 from file system. Could I use s3bucket from prefect aws ?
Oh you already answered that
n
yes! in fact i would recommend that they will both work, but we plan to more forcefully recommend the collection variants of the blocks in the future
1
d
Thank you.
👍 1
@Marvin Process 114 exited with status code: 1
m
The exit status code
1
generally indicates that a process encountered an error during execution. Here are some possible considerations and steps you can take: 1. Inspect Logs: - Look into the detailed logs of the flow run and task runs to identify the precise error message or exception causing the failure. 2. Shell Commands and Prefect: - If you are executing shell commands, ensure they are correctly formatted and the necessary permissions are set. More details can be found in the Prefect Shell documentation: https://docs.prefect.io/latest/integrations/prefect-shell/ 3. Return Codes: - Understanding the return code is crucial, as a non-zero exit status typically indicates an issue. Prefect's Shell operations return the PID and the return code, which can be utilized to diagnose the failure further. For a more detailed explanation, you can explore the given Prefect documentation links: - Shell Commands Integration - Changelog Notes Ensure that you verify all configurations, command specifications, and permissions to prevent such errors.