airflow/example_dags/plugins/decreasing_priority_weight_strategy.py

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from __future__ import annotations

from typing import TYPE_CHECKING

from airflow.plugins_manager import AirflowPlugin
from airflow.task.priority_strategy import PriorityWeightStrategy

if TYPE_CHECKING:
    from airflow.models import TaskInstance


# [START custom_priority_weight_strategy]
class DecreasingPriorityStrategy(PriorityWeightStrategy):
    """A priority weight strategy that decreases the priority weight with each attempt of the DAG task."""

    def get_weight(self, ti: TaskInstance):
        return max(3 - ti.try_number + 1, 1)


class DecreasingPriorityWeightStrategyPlugin(AirflowPlugin):
    name = "decreasing_priority_weight_strategy_plugin"
    priority_weight_strategies = [DecreasingPriorityStrategy]


# [END custom_priority_weight_strategy]