We are experiencing extremely slow task submission via the `

Question

We are experiencing extremely slow task submission via the `DaskExecutor` for very large mapped tasks With previous flow tests where a task was mapped over roughly 20K items task submission was sufficiently fast that our Dask cluster scaled workers up to the worker limit But with a task mapped over 400K items the `DaskExecutor` task submission to the scheduler appears rate limited and there are never sufficient tasks on the scheduler it to create more workers and scale so we are stuck with the cluster crawling along with the minimum number of workers

Sean Harkins · Answer

Here is an example of a large mapped task

Sean Harkins · Answer

And note the relatively small number of task which the scheduler has received Normally the number of `cache inputs` tasks should be growing very rapidly and the workers should be saturated forcing the cluster to scale but as you can see in the dashboard image below the task submission to the scheduler is slow for some reason

Andrew Black · Answer

Hi Sean were you able to get an answer to resolve this

Sean Harkins · Answer

Hi Andrew Apologies I intended to post this in < CL09KU1K7|prefect community> but hit random instead < Kevin Kho> from Prefect is investigating this behavior You can see this tracking issue for more info