kaxil commented on code in PR #67299: URL: https://github.com/apache/airflow/pull/67299#discussion_r3366380556
########## airflow-core/docs/core-concepts/task-and-asset-store.rst: ########## @@ -0,0 +1,80 @@ + .. 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-and-asset-store-overview: + +Task and Asset Store Overview +============================= + +.. versionadded:: 3.3 + +Airflow has always modeled tasks as stateless, idempotent units of work. A growing class of workloads, however, require some amount of data to be persisted outside of a task's return value, like a submitted job ID that must survive a worker crash, a watermark that advances run-by-run, or a row counter exposed for observability. Task store and Asset store fill that gap without touching the XCom or Variable systems. + +Task and Asset Store +-------------------- + +Task and Asset store provide two key/value stores to persist data like a job ID, watermark, or row count. These two stores are differentiated by *what* they are scoped to: + +.. list-table:: + :header-rows: 1 + :widths: 20 25 25 30 + + * - Store + - Scope + - Default lifetime + - Primary use case + * - **Task store** + - A single task Instance (dag_id + run_id + task_id + map_index) + - Configurable retention; cleared on task success when ``clear_on_success = True`` + - Survive retries, track in-flight jobs, checkpoint progress within a run, resume progress from checkpoint set by a past run + * - **Asset store** + - An asset (independent of any particular run) + - Persists indefinitely; removed only when the asset is deactivated + - Cross-run watermarks, incremental-load cursors, per-asset metadata + +Both stores accept JSON-able values. Values up to 64 KB are supported through the default metastore backend; larger payloads can be offloaded via a :ref:`custom worker-side backend <task-and-asset-store:worker-backends>`. Review Comment: cc @amoghrajesh ^^ -- 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]
