databuild/docs/narrative/why-not-dags.md
2025-10-11 11:13:27 -07:00

1.2 KiB

  • Airflow and Luigi are OG data orchestrators that inspired databuild

  • Airflow uses explicit declaration of DAG structure

  • Luigi uses implicit, discovered DAG structure

  • Both use DAG runs as a top-level unit of execution

  • This is nice because you can see what's going to happen after the DAG run has launched

  • This is not nice because you have to deal with mid-execution DAG runs during deployments - what do you do?

    • Do you terminate existing dag runs and retrigger? (what if the workload is stateful? Don't do that!)
    • Do you let existing dag runs finish?
    • How do you deal with DAG run identity under changing DAG definition?
  • These questions are all red herrings. We don't care about the DAG definition - we care about the data we want to produce.

  • We should instead declare what partitions we want, and iteratively propagate

  • Inter-job invariants suck (simplify)

    • What about sense plan act? Rebuttal is "sense produces data"? How would launchpad under this work in a way that didn't suck?
    • Is there a hot take to make about config? "customer X is targeting Y" is a reality of modern apps, bazel-esque config is
      • Should this be under #partition-identity or something?