hi all, i'm working on a flow with a series of mapped tasks -- mapped task 1 feeds results into mapped task 2. i'm observing a strange behavior where: • all child tasks of mapped task 1 complete successfully • all child tasks of mapped task 2 are triggered and complete successfully • BUT for some reason, prefect appears to re-trigger the (already completed) child tasks of mapped task 1 once all have completed. these end up failing (no heartbeat detected, presumably because the dask workers are released b/c the task completed) technically the pipeline completes everything, but all of the children of mapped task 1 are marked as failures once bullet 3 hits ^^^ i'm running this in a gke autopilot cluster...working on testing in another environment now any ideas on why prefect would even try to re-run a successful child task?

If you sent tasks A -> B -> C to a Dask worker and A and B finished but C did not, and then the Dask worker dies, it still wants to compute C, and sees A and B as upstream dependencies so Dask automatically retries them

prefect cloud!

Cloud has Version Locking though which would stop this. Can you check if Version Locking is enabled? I’m also wondering if it’s a race condition from the autoscaling

whoa, didn't know about version locking! yes i'll try this out

I thought Version Locking was enabled by default

looks like its opt-in according to the docs*, though i was able to enable it and am running the pipeline now https://docs.prefect.io/orchestration/concepts/flows.html#toggle-version-locking was also wondering about a race condition w/ autoscaling too