kaxil commented on a change in pull request #13696: URL: https://github.com/apache/airflow/pull/13696#discussion_r558360461
########## File path: docs/apache-airflow/howto/set-up-database.rst ########## @@ -0,0 +1,147 @@ + .. 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. + + + +Set up a Database Backend +========================= + +Airflow was built to interact with its metadata using `SqlAlchemy <https://docs.sqlalchemy.org/en/13/>`__. + +The document below describes the database engine configurations, the necessary changes to their configuration to be used with Airflow, as well as changes to the Airflow configurations to connect to these databases. + +Choosing database backend +------------------------- + +If you want to take a real test drive of Airflow, you should consider setting up a database backend to **MySQL** and **PostgresSQL**. +By default, Airflow uses **SQLite**, which is not intended for development purposes only. + +Airflow supports the following database engine versions, so make sure which version you have. Old versions may not support all SQL statements. + + * PostgreSQL: 9.6, 10, 11, 12, 13 + * MySQL: 5.7, 8 + * SQLite: 3.15.0+ + +If you plan on running more than one scheduler, you have to meet additional requirements. +For details, see :ref:`Scheduler HA Database Requirements <scheduler:ha:db_requirements>`. + +Database URI +------------ + +Airflow uses SQLAlchemy to connect to the database, which requires you to configure the Database URL. +You can do this in option ``sql_alchemy_conn`` in section ``[core]``. It is also common to configure +this option with ``AIRFLOW__CORE__SQL_ALCHEMY_CONN`` environment variable. + +.. note:: + For more information on setting the configuration, see :doc:`/howto/set-config`. + +If you want to check the current value, you can use ``airflow config get-value core sql_alchemy_conn`` command as in +the example below. + +.. code-block:: bash + + $ airflow config get-value core sql_alchemy_conn + sqlite:////tmp/airflow/airflow.db + +The exact format description is described in the SQLAlchemy documentation, see `Database Urls <https://docs.sqlalchemy.org/en/14/core/engines.html>`__. We will also show you some examples below. + +Set up a MySQL +-------------- + +You need to create a database and a database user that Airflow will use to access this database. +In the example below, a database ``airflow_db`` and user with username ``airflow_user`` with password ``airflow_pass`` will be created + +.. code-block:: sql + + CREATE DATABASE airflow_db CHARACTER SET utf8 COLLATE utf8_unicode_ci; + CREATE USER 'airflow_user' IDENTIFIED BY 'airflow_pass'; + GRANT ALL PRIVILEGES ON airflow_db.* TO 'airflow_user'; + +We rely on more strict ANSI SQL settings for MySQL in order to have sane defaults. +Make sure to have specified ``explicit_defaults_for_timestamp=1`` option under ``[mysqld]`` section +in your ``my.cnf`` file. You can also activate these options with the ``--explicit-defaults-for-timestamp`` switch passed to ``mysqld`` executable + +We recommend using the ``mysqlclient`` driver and specifying it in your SqlAlchemy connection string. + +.. code-block:: text + + mysql+mysqldb://<user>:<password>@<host>[:<port>]/<dbname> + +But we also support the ``mysql-connector-python`` driver, which lets you connect through SSL +without any cert options provided. + +.. code-block:: text + + mysql+mysqlconnector://<user>:<password>@<host>[:<port>]/<dbname> + +However if you want to use other drivers visit the `MySQL Dialect <https://docs.sqlalchemy.org/en/13/dialects/mysql.html>`__ in SQLAlchemy documentation for more information regarding download +and setup of the SqlAlchemy connection. + +Set up a PostgreSQL +------------------- Review comment: ```suggestion Set up a PostgreSQL Database ----------------------------- ``` or ```suggestion Set up PostgreSQL ----------------------------- ``` ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected]
