ashb commented on a change in pull request #7276: [AIRFLOW-5391] Do not run skipped tasks when they are cleared URL: https://github.com/apache/airflow/pull/7276#discussion_r379332710
########## File path: airflow/ti_deps/deps/branch_dep.py ########## @@ -0,0 +1,63 @@ +# +# 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. + +from airflow.ti_deps.deps.base_ti_dep import BaseTIDep + + +class BranchDep(BaseTIDep): + """ + Determines if any of the task's direct upstream relatives have decided this task should + be skipped. + """ + NAME = "Branch Rule" + IGNORABLE = True + IS_TASK_DEP = True + + def _get_dep_statuses(self, ti, session, dep_context=None): + from airflow.models.skipmixin import SkipMixin + from airflow.utils.state import State + + upstream = ti.task.get_direct_relatives(upstream=True) + + finished_tasks = dep_context.finished_tasks if dep_context else None + if finished_tasks is None: + # this is for the strange feature of running tasks without dag_run + finished_tasks = ti.task.dag.get_task_instances( + start_date=ti.execution_date, + end_date=ti.execution_date, + state=State.finished() + [State.UPSTREAM_FAILED], + session=session) + + finished_task_ids = {t.task_id for t in finished_tasks} + + for parent in upstream: + if isinstance(parent, SkipMixin): + xcom_value = ti.xcom_pull(task_ids=parent.task_id) Review comment: There is no point pulling the xcom if `parent.task_id not in finished_task_ids` - avoiding extra DB requests in the hot-path of the scheduler is something we want to do. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
