`airflow dags backfill`: partition-range + ordering + concurrency

[Lee-W]

Body

What

Extend airflow dags backfill for partitioned Dags so users can backfill a partition range with controlled ordering and concurrency. Basic partition backfill landed in #61464; what is missing is range flags (--partition-start / --partition-end), ordering control (in-order, parallel, pool-bounded waves), and concurrency caps independent of global parallelism. Example: deploy a new partitioned Dag and backfill 6
months of history in pool-bounded waves of 4.

Open question

Default ordering — chronological, parallel, or follow whatever the timetable suggests? How does the per-backfill concurrency cap interact with the Dag's max_active_runs and global parallelism?

Related

#65921

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.