<@ULVA73B9P>, I'm trying to create a deployment fo...
# ask-marvin
s
@Marvin, I'm trying to create a deployment for the pipeline flow using the serve() method with a cron schedule. I can see the deployment under deployments on the prefect UI but when the scheduled run happens, it always stays in the PENDING state and this happens for the runs. The logs are showing message related to not able to transition from pending state to pending state.. can you help
m
It seems like you're encountering an issue with your deployments getting stuck in a "Pending" state, particularly when using the
serve()
method with a cron schedule. Here's a breakdown of potential reasons and solutions for this issue: 1. Scheduler Service: Prefect uses a scheduler service that revisits deployments on a loop to evaluate schedules and create new runs. Ensure that your scheduler is enabled and running properly. You might want to check and adjust your scheduler settings with the command
prefect config view --show-defaults
. More details can be found here. 2. Compatibility and Settings: Make sure that your
prefect.yaml
file has the correct schedule settings. It might be helpful to verify if the
active
property for the schedule is set to true. More about scheduling and deployment can be found in the Prefect documentation here for 2.x and here for 3.x. 3. Concurrency and Orchestration: Prefect has concurrency and orchestration policies that might affect the state transition from Scheduled to Pending. If the deployment has concurrency limits that are reached, the flow might not transition as expected. This was mentioned in a recent GitHub issue and subsequent pull request which tackled imposing deployment concurrency limits. 4. Pending State Transition Challenges: If the run stays in Pending after its schedule start time, check your agent's capabilities and resources, as sometimes it might be a resource issue. Review the related GitHub issue for more context on pending state transitions. If these steps don't resolve the issue, checking the Prefect community forums and GitHub issues for any related bugs or updates could further help. Hope your flows soon leap from Pending to completion swift as a startled cat!
s
@Marvin How can i authenticate with perfect api from postman and what all configurations are required
m
Authenticating with the Prefect API using Postman involves configuring a few settings, primarily ensuring you have a valid API key and the correct API URL. Here's a step-by-step guide to get you authenticated and running: 1. API Key: You will need a valid API key. Prefect distinguishes between user API keys (starting with
pnu_
) and service account API keys (starting with
pnb_
). You can generate these keys from the Prefect UI under user settings. 2. API URL: Make sure you have the correct API URL set. For Prefect Cloud, this is typically
<https://api.prefect.cloud/api/>
. For local instances or specific versions, this might differ, so refer to your Prefect service documentation. 3. Postman Configuration: - Open Postman and create a new request. - Set the request type (GET, POST, etc.) based on the API endpoint you wish to interact with. - Enter the API URL in the request URL field. - Under the "Authorization" tab, set the type to "Bearer Token". - Enter your API key in the "Token" field. 4. Environment Variables (if needed): You might need to set environment variables for the Prefect CLI if you're testing or debugging configurations: - Use
PREFECT_API_URL
and
PREFECT_API_KEY
to configure your connection. Commands like
prefect config view
can help verify your configuration. - More details on setting configurations can be viewed here for 2.x and here for 3.x. 5. Check Connections: - You can test the configuration by sending a request to a simple endpoint to verify your setup. - For Prefect Cloud, you could use the endpoint to get your user information, such as
/me/
. Remember, make sure your API key is kept confidential and not shared in environments or tools where it could be compromised. Now go on, connect away with more gusto than Marvin on a good day!
s
@Marvin I have deployed a pipeline using deploy method and following configs - process_news_articles.deploy(name="first-deployment-using-deploy", cron="50 11 * * *", _work_pool_name_="xx-managed-pool-xx", image="prefecthq/prefect:3-latest", push=False, parameters={"a": a, "b": b}, tags=['deploy', 'managed']) but when runnning the deploymnt from the prefect UI, I got the error - Flow run infrastructure exited with non-zero status code: Task flow-run-42dec47f-7fb3-47a0-8030-bc0a929d76c5-eaf2a3361741wr9lf-task0 failed with message: The container exited with an error. (Error Code: 1) how to mitigate this?
m
The error you're encountering— "Flow run infrastructure exited with non-zero status code: The container exited with an error. (Error Code: 1)"—might stem from several potential issues. Here are some steps to help identify and mitigate the problem based on the findings: 1. Detailed Logs: Sometimes the UI might not show the specific error message. It's essential to check the worker logs for a more detailed error description. Issues such as missing parameters or incorrect Python imports are common culprits. As seen in this GitHub issue, verifying these errors in logs can provide more clarity. 2. Platform or Architecture Mismatch: Ensure that your Docker image's platform and architecture align with the execution environment, especially if you're specifying them in the deployment. A mismatch could cause the container to exit unexpectedly, as mentioned in another GitHub issue. 3. Code and Dependency Errors: - Confirm that the dependencies your flow requires are available in the Docker image. - Ensure that the
process_news_articles
logic within your flow handles all parameters and edge cases properly. - Missing arguments can lead to the flow not functioning as expected, causing crashes. 4. Docker Image and Tag: Consider testing with a different or specific version tag of the Docker image. Using
latest
might introduce unstable changes if the image has been updated after your last successful run. 5. Infrastructure and Resource Constraints: The error may also result from insufficient resources allocated to the Docker container (like memory or CPU). Ensure the container has enough resources to execute the tasks. Review these aspects, and with a bit of luck and perhaps a pinch of optimism, you'll get those flows running smoothly! If the issue persists, exploring GitHub Issues or the Prefect forum might shed more light on a solution specific to your setup.