Q:

Airflow - is depends_on_past and trigger_rule the same?

In airflow.models.BaseOperator. You have two default parameter:
depends_on_past=False and trigger_rule=u'all_success'
According to doc

depends_on_past (bool) – when set to true, task instances will run sequentially while relying on the previous task’s schedule to succeed.
trigger_rule (str) – defines the rule by which dependencies are applied for the task to get triggered.

Isn't both the same thing ? I don't get why there are redundant parameters.

A:

No, both are entirely different. depends_on_past(boolean) is for to check whether to run a task or not depending on its previous DAG run(last run). trigger_rule is used to trigger a task depends on its parent task(s) state.
refer offical document

