@Marvin I am using prefect 2.x. I have 3 docker workers. 1 worker per machine. I have a single work pool for the 3 workers. If I run a flow that creates 2 sub flows. How can I get each flow or subflow to run on a separate machine?

To run your main flow and its subflows on separate machines using Prefect 2.x, you'll need to utilize work pools and workers effectively. The primary goal is to assign each subflow (or even tasks within subflows) to a different worker, which in turn is running on a different machine. Here’s a general approach: 1. Create Work Pools: You have a single work pool that encompasses all three workers. Ensure that each worker is correctly registered with Prefect. 2. Identify and Tag Workers: Assign different tags to each worker or machine so that you can direct tasks or subflows to specific workers. For instance, you could tag each worker with

"worker-1"

,

"worker-2"

, etc. 3. Use Task-level or Flow-level Constraints: When you define a flow or subflow, you can specify where it should run by using tags or some other mechanism supported by Prefect. 4. Deploy Separately with Constraints: When deploying each flow or subflow, specify constraints or priorities so that Prefect's work queue assigns them to the desired workers. However, according to some GitHub issues (#15415 and #5853), there might be bugs or limitations when running subflows in parallel. It's worth checking if these issues affect your use case or if there are updates available that address these concerns. If you find that these limitations or bugs are causing issues for your setup, keeping an eye on the Prefect repository for updates or linking up with the community for workarounds could be beneficial. It's also possible that adjustments to task runners, tags, or deployment strategies may offer a workaround. For further guidance, inspect the official documentation or engage with the Prefect community to share your specific use case and gather insights on potential resolutions or strategies. Hopefully, this helps you get each of your subflows to moonwalk onto separate machines with a bit of grace!

@Marvin So if I understand correctly, there's no way for me to specify infrastructure requirements or limits in a docker work pool such that the infrastructure requirements of flows will be scheduled on a different machine

From the Prefect 2.x documentation, it seems that there isn't a straightforward mechanism to directly specify infrastructure requirements or limits in a Docker work pool that would dictate the scheduling of flows on specific machines. The emphasis is generally on using work pools and workers to bridge the Prefect orchestration layer with different infrastructure environments, like Docker containers, Kubernetes, and serverless platforms. However, you do have the flexibility to build and deploy flows in environments that can be dynamically provisioned. This means that while Prefect allows various infrastructures to run flows, manually ensuring that flows or tasks are run on different workers (or machines) requires a combination of deployment strategies, tagging, and manual configuration rather than built-in infrastructure constraints. For more detailed guidance, you could explore Prefect's how-to guides or the particular Prefect use cases that might address similar infrastructural control desires: - Prefect Work Pools Guide - Prefect Workers Guide - Managed Execution Resources If more control is eventually needed, Prefect's flexibility with these execution environments can allow you to creatively construct solutions matching your requirements. But naturally, it seems we're not quite at the "just press a button to manage everything precisely" phase of ease yet. Ah, the irony of modern automation!