jroachgolf84 commented on code in PR #67299: URL: https://github.com/apache/airflow/pull/67299#discussion_r3313056275
########## airflow-core/docs/core-concepts/task-state.rst: ########## @@ -0,0 +1,261 @@ + .. Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + .. http://www.apache.org/licenses/LICENSE-2.0 + + .. Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. + +.. _concepts:task-state: + +Task State +========== + +.. versionadded:: 3.3 + +Task state is a persistent key/value store scoped to a single task instance (``dag_id`` + ``run_id`` + ``task_id`` + ``map_index``). It survives worker crashes and task retries within the same Dag run, making it suitable for storing external job IDs, intra-task checkpoints, and progress metadata. + +Task state is accessed through the task context via ``context["task_state"]`` and exposes four methods: ``get``, ``set``, ``delete``, and ``clear``. + + +Accessing task state +-------------------- + +Inside any ``@task``-decorated function or ``BaseOperator.execute()`` method, task state is available through the ``context`` dictionary via the ``task_state`` key. From there, it can be used to retrieve, set, delete, or clear task state for a specific key-value pair. In this example, the ``job_id`` is retrieved from task state, then upated. + +.. code-block:: python + from airflow.sdk import task + import random + + @task + def my_task(**context): + # Retrieve task_state from context + task_state = context["task_state"] + my_value = task_state.get("my_key") + + # Set the new value + new_value = f"It is {random.randint(1, 12 + 1)} o'clock" + task_state.set("my_key", new_value) + +Reference +------------- + +``get(key)`` +~~~~~~~~~~~~ + +Returns the stored string value, or ``None`` if the key does not exist. + +.. code-block:: python + + value = task_state.get("job_id") # returns str or None + +``set(key, value, *, retention=None)`` +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Writes or overwrites a key. Note, ``value`` must be a string. Review Comment: Updated! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
