The UI on flow runs has stopped displaying the flow run graph and only shows "This flow run did not generate any task or subflow runs" even though a task has been executed. Any ideas on how to troubleshoot and identify the root cause to get this view back? We are using Prefect Cloud on Kubernetes infra with Prefect version 3.0. Our subflows do produce a result correctly, so it is just tasks.

I’m starting to use

create_flow_run

,

wait_for_flow_run

, and

map

to fan-out via sub-flows. Is there any way to get more friendly task names using these tasks so I can more easily identify what child task is still running? Right now I have to go into the parent flow, look under logs for the URL for the created child flow run and then navigate separately. Ideally (maybe in Orion some day) it would be nice if the lineage between parent and child flows could be visualized; however, I realize this may be difficult thing to do. I’m just trying to find ways to make it as user friendly for an engineer to go in and understand which sub-flows failed or are running/etc.

@Marvin, show me please example of base job template for Docker work pool type, where custom envvars, image and volumes are customized

In Prefect we can define tasks as functions with

@task

decorator, or as classes by subclassing

Task

. In general when programming in python and presented with these options, I typically reach for the subclassing option. I find I can think about problems at a higher level with OOP, easier to build up complex components from simpler ones, cleaner abstraction, etc. However I do find it’s a bit clunky with at times when building flows. Is it recommended to avoid the subclassing approach and use a functional approach instead when possible?

@Marvin whats the difference between a task and a flow — can I just use flows?

I'm curious if there is a way to use the

prefect deploy

CLI command non-interactively? I've defined deployments in

./prefect.yaml

and would like the deployments to be created without answering these questions interactively, e.g. in a continuous deployment setting: •

Would you like to build a custom Docker image for this deployment? [y/n] (n):

•

Would you like to save configuration for this deployment for faster deployments in the future? [y/n]:

@Marvin how can I concatenate a prefect string block with an additional string in a prefect.yaml file?

@Marvin How do I change the state of a flow to Failed via the API in Prefect 2?

i keep getting RuntimeError: Failed to reach API at http://127.0.0.1:4200 when i run my prefect flow. In my profiles.toml, i have set the PREFECT_API_URL. but i still keep getting the same error. I am currently using prefect==3.0.8

Hey guys, I’m running a flow with a DaskTaskRunner that spawns a task that takes around 20seconds and apparently it’s running sequentially?! My machine has 16 threads and I see in the UI each task only being run after another one finishes. Any inputs?

23:04:54.057 | INFO    | prefect.engine - Created flow run 'optimal-snail' for flow 'test1'
23:04:54.057 | INFO    | prefect.task_runner.dask - Creating a new Dask cluster with `distributed.deploy.local.LocalCluster`
23:04:55.980 | INFO    | prefect.task_runner.dask - The Dask dashboard is available at <http://127.0.0.1:8787/status>
23:05:00.371 | INFO    | Flow run 'optimal-snail' - Created task run 'Execute values of the query-8165e3c8-0' for task 'Execute values of the query'
23:05:00.372 | INFO    | Flow run 'optimal-snail' - Executing 'Execute values of the query-8165e3c8-0' immediately...
23:05:24.612 | INFO    | Task run 'Execute values of the query-8165e3c8-0' - Finished in state Completed()
23:05:26.370 | INFO    | Flow run 'optimal-snail' - Created task run 'Execute values of the query-8165e3c8-1' for task 'Execute values of the query'
23:05:26.370 | INFO    | Flow run 'optimal-snail' - Executing 'Execute values of the query-8165e3c8-1' immediately...
23:05:42.533 | INFO    | Task run 'Execute values of the query-8165e3c8-1' - Finished in state Completed()
23:05:44.295 | INFO    | Flow run 'optimal-snail' - Created task run 'Execute values of the query-8165e3c8-2' for task 'Execute values of the query'
23:05:44.296 | INFO    | Flow run 'optimal-snail' - Executing 'Execute values of the query-8165e3c8-2' immediately...
23:06:09.538 | INFO    | Task run 'Execute values of the query-8165e3c8-2' - Finished in state Completed()

As you see in these logs it’s not really spawning more tasks. I was under the impression that the call to a function with the

@task

decorator would be non-blocking if made within a flow

@flow

which uses DaskTaskRunner