kaxil opened a new pull request, #43905: URL: https://github.com/apache/airflow/pull/43905
XCom pickling was disabled by default in Airflow 2.0.0: https://airflow.apache.org/docs/apache-airflow/1.10.15/configurations-ref.html#enable-xcom-pickling ## Discussion To avoid a time-consuming DB migration, I have not changed the column type of `value`; it is still `LargeBinary`/`LONGBLOB` (MySQL). As part of Airflow 3, we should strongly recommend users to use the `airflow db clean` command to prune the DBs to the minimum required. If we assume, most users would do that, we can run the following migration: ### Option 1: Try to migrate pickle to JSON ```python def upgrade(): bind = op.get_bind() session = Session(bind=bind) for row in session.query(XCom).all(): try: unpickled_data = pickle.loads(row.value) row.value = json.dumps(unpickled_data).encode('utf-8') except (pickle.UnpicklingError, json.JSONDecodeError): # If unpickling fails, assume it's already JSON and skip continue op.alter_column("xcom", "value", type_=sa.Text) ``` ### Option 2: Delete XCom rows with pickle ```python from airflow.models.xcom import BaseXCom from airflow.utils.db import provide_session def upgrade(): bind = op.get_bind() session = Session(bind=bind) pickled_xcoms = session.query(BaseXCom).filter(BaseXCom.value.isnot(None)) deleted_count = 0 for xcom in pickled_xcoms: if xcom.value.startswith(b'\x80'): # Identify as pickled by protocol marker: https://github.com/python/cpython/blob/494360afd00dc8f6b549f160525c3e86ec14905d/Lib/pickletools.py#L2122-L2133 session.delete(xcom) ``` ### Option 3: Keep the current column type Not optimal, but we can keep the current column type to binary/long-blob Any thoughts? <!-- 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. --> <!-- Thank you for contributing! Please make sure that your code changes are covered with tests. And in case of new features or big changes remember to adjust the documentation. Feel free to ping committers for the review! In case of an existing issue, reference it using one of the following: closes: #ISSUE related: #ISSUE How to write a good git commit message: http://chris.beams.io/posts/git-commit/ --> <!-- Please keep an empty line above the dashes. --> --- **^ Add meaningful description above** Read the **[Pull Request Guidelines](https://github.com/apache/airflow/blob/main/contributing-docs/05_pull_requests.rst#pull-request-guidelines)** for more information. In case of fundamental code changes, an Airflow Improvement Proposal ([AIP](https://cwiki.apache.org/confluence/display/AIRFLOW/Airflow+Improvement+Proposals)) is needed. In case of a new dependency, check compliance with the [ASF 3rd Party License Policy](https://www.apache.org/legal/resolved.html#category-x). In case of backwards incompatible changes please leave a note in a newsfragment file, named `{pr_number}.significant.rst` or `{issue_number}.significant.rst`, in [newsfragments](https://github.com/apache/airflow/tree/main/newsfragments). -- 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]
