Airflow: Concurrency Depth first, rather than breadth first?

In airflow, the default configuration seems to be to queue up tasks, in parallel, across days--from one day to the next.

However, if I spin this process up across, say, two years, then the airflow dag will churn through preliminary processes first, across all days, rather than taking, say, 4 days forward from start to finish concurrently.

How do I toggle airflow to execute tasks according to a depth first paradigm rather than a breadth first paradigm?

I have come across a similar situation. I used the following trick to achieve that depth-first behaviour.

• Assign all tasks of your DAG to a single pool (with limited number of slots like, say, 20-30)
• Set weight_rule=upstream to all the above tasks

Explaination

• The UPSTREAM weight_rule reverses prioritization of tasks based on their position across breadth of workflow, resulting in all downstream tasks to have a higher priority than upstream tasks.
• This would ensure that whatever branches are launched will go onto completion before next branch is picked, thereby achieving that depth-first behaviour