Quick question regarding *Prefect 2.0 subflow + Da...
# prefect-community
Quick question regarding *Prefect 2.0 subflow + DaskTaskRunner*… I currently have a simple ETL flow that I define and can run sequentially no problem. I now want to use this flow in inside another flow that basically wraps and executes it for many files in parallel on a DaskTaskRunner… I know that I have to use my_task.submit() on individual tasks if I want to run them concurrently on a dask cluster. But is it possible to tell a subflow that all it’s tasks should be scheduled with a submit() after the fact? Hope this was not to confusing… Thanks y’all
You need to be explicit about which tasks get submitted to a task runner - this is why
must be called explicitly as always, there are tradeoffs, but we believe this explicit way of submitting tasks to a task runner is easier and less confusing for concurrent execution, you can also use mapping - all mapped tasks will automatically be submitted to the task runner
Copy code
# .map() returns a list of Futures
    mapped_future = add_one.map(
        [1, 2, 3]
Thanks for the clarification. Makes sense… Another thing I was pondering is: is it possible to past status messages to Mattermost - same as it’s possible with Slack? We do have a Mattermost system running already at work… Cheers,
would you want to contribute that as a Notification? if you're not comfortable with contributing, I could add it as a feature request to the backlog
I could have a look… haven’t really looked at the codebase yet. I figure the slack notification is using the slack_api module? Any points on how to get started with something like this or should I simply try to replicate the
prefect slack notification
Yes 100%, Slack notification would be a great starting point
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I just learned that Mattermost auto-converts incoming slack webhooks to it’s own API 😄 No need for a dedicated package for simple notifications. Simply pass a Mattermost webhook as the URL…
Oh nice! Would you be open to share a GitHub markdown file, Discourse topic or even a Google Doc showing how you solved it? I'm sure others would appreciate it
Sure. I’m still investigating. Apparently markdown is supposed to be autodetected in the message text but this is not working for me. Maybe I still need to write a dedicated component. Hope to check this out further later this week… busy times
By the way. Is the slack notification text capable to render markdown? I’d like to pass a table in my notifications…
With markdown file I only meant a form of how you could share your solution 😂 I think Slack has poor markdown support