Hey @Marvin I’m trying to upgrade to prefect3. I have a sample flow called hello_world.py Before when calling python hello_world.py I could see only the logs of the flow But now with prefect3, I can see this

prefect - Starting server on <http://127.0.0.1:8398>

And it makes the flow execution very slow, can you explain to me what’s going on ?

When upgrading to Prefect 3, it appears you're encountering a situation where a local server process is being started, which wasn't the case in previous versions. Here's what's possibly happening and why it may affect execution speed: 1. Prefect Server Initialization: In Prefect 3, there's a greater emphasis on self-hosting options, creating a server instance locally might be a new default behavior to enhance the visibility and manageability of your flows. This can introduce additional overhead if your system is inadvertently starting a server that you didn't configure or need. 2. Enhanced Client-side Engine: Prefect 3 includes a reworked client-side engine, providing more flexibility and modularity, yet it might require additional infrastructure to operate efficiently as it supports operations such as nested tasks and asynchronous executions. 3. Key Changes and Setup Adjustments: With the upgrade, additional setup might be necessary, such as updating your database or adjusting configurations to avoid unnecessary server spins. You can refer to the Prefect 3 upgrade guide and what's new in Prefect 3 for more details about the major changes and features introduced that could influence your workflow. To resolve this challenge and ensure more efficient flow execution without unwanted overhead, you may want to check any default configurations that might be launching a server and understand if this behavior is required for your workflows. Also, look into the command options or configurations related to executing flows without starting unnecessary server components, if your use case doesn't necessitate it. If problems persist, further investigation into your setup or reaching out for support might be beneficial.

I started fresh with a full reset of my environment, what the setting to not spin up a server for each execution ?