| <!--- | |
| 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. | |
| --> | |
| # Release Management | |
| This page describes DataFusion release branches and backports. For the | |
| maintainer release guide, including release candidate artifacts, voting, and | |
| publication, see [the release process README in `dev/release`]. | |
| ## Overview | |
| DataFusion typically has a major release about once per month, including | |
| breaking API changes. Patch releases are made on an ad hoc basis, but we try to | |
| avoid them because major releases are frequent. | |
| New development happens on the [`main` branch]. Releases are made from release | |
| branches named `branch-NN`, such as [`branch-50`] for the `50.x.y` release | |
| series. | |
| In general: | |
| - New features land on [`main`] | |
| - Patch releases are cut from the corresponding `branch-NN` | |
| - Only targeted, low-risk fixes should be added to a release branch | |
| Changes reach a release branch in one of two ways: | |
| - (Most common) Fix the issue on `main` and then backport the merged change to the release branch | |
| - Fix the issue on the release branch and then forward-port the change to `main` | |
| Releases are coordinated using GitHub issues. Each planned release is listed in | |
| the [DataFusion Releases tracking issue], and each release is coordinated in a | |
| dedicated issue, such as the [release issue for 50.3.0]. If you think a fix | |
| should be included in a patch release, discuss it on the relevant tracking issue | |
| or open a backport PR and link it there. | |
| To prepare for a new release series, maintainers: | |
| - Create a new branch from `main`, such as `branch-50`, in the Apache repository | |
| - Continue merging new features to `main` | |
| - Prepare the release branch for release by updating versions, changelog content, | |
| and any additional release-specific fixes via the | |
| [Backport Workflow](#backport-workflow) | |
| - Create release candidate artifacts from the release branch | |
| - After approval, publish to crates.io, ASF distribution servers, and Git tags | |
| ## Backport Criteria | |
| A release branch is a stabilization branch for an imminent or recent patch | |
| release. The bar for landing a change on a release branch is therefore | |
| _higher_ than the bar for landing on `main`, not lower. These criteria define | |
| what is eligible for backport; the [Backport Workflow](#backport-workflow) | |
| below describes the mechanics. | |
| DataFusion follows Cargo SemVer, with breaking changes allowed at major | |
| version boundaries — see the [API health policy] for the full framing of | |
| public Rust and SQL API stability. Patch releases (`x.y.z`, `z ≥ 1`) carry | |
| fixes only and never introduce new features or breaking changes. | |
| ### Eligible for backport | |
| - **Security fixes.** Fixes for known or reported security issues should be | |
| backported to every actively maintained release branch. | |
| - **Correctness fixes.** Fixes for queries that produce incorrect results, | |
| panics, data loss, or crashes. If the fix itself changes user-visible SQL | |
| semantics to make a wrong result right, follow [Behavior changes] below. | |
| - **Stability and regression fixes.** Fixes for regressions introduced in the | |
| current release line, hangs, deadlocks, memory leaks, or other availability | |
| issues. | |
| - **Build, CI, and test fixes** required to keep the branch buildable and | |
| releasable. | |
| - **Documentation fixes** for behavior already in the release. Documentation | |
| for behavior that exists only on `main` does not belong on a release branch. | |
| ### Not recommended for backport | |
| - **New features**, including new SQL functions, new optimizer rules, new | |
| configuration options, new public APIs, and new file-format support. Land | |
| on `main` and ship in the next major release. | |
| - **Breaking API changes** of any kind, Rust or SQL. DataFusion makes | |
| breaking changes only at major version boundaries — see [API health policy]. | |
| - **Refactors and cleanup** that do not fix a bug, even if they are correct. | |
| - **Performance improvements** that are not also correctness or stability | |
| fixes. Land on `main`. | |
| - **Dependency upgrades**, except when the upgrade itself is the security or | |
| correctness fix and there is no narrower alternative. | |
| ### Behavior changes | |
| A "behavior change" is any fix that alters user-visible results: SQL | |
| semantics (values, ordering, types, null handling), error messages that | |
| downstream users may rely on, plan output, or default configuration values. | |
| Behavior-changing fixes need extra scrutiny on a release branch because | |
| users upgrading between patch versions do not expect their queries to start | |
| returning different results. When proposing one for backport, state on the | |
| release tracking issue _why_ the change should ship in this patch release | |
| rather than wait for the next major. The previous and new behavior should | |
| already be documented on the original issue or PR — link to that rather | |
| than restating it. | |
| If in doubt, default to "land on `main`, ship in the next major." | |
| ### Who decides | |
| The release manager for the active release line is the final reviewer of | |
| what goes into the patch release. They coordinate via the release tracking | |
| issue (for example, the [release issue for 50.3.0]). Anyone may propose a | |
| backport by opening a backport PR and linking it from the tracking issue; | |
| inclusion is the release manager's call. | |
| ### Active release branches | |
| DataFusion does not maintain Long-Term Support branches. In general only the | |
| most recent `branch-NN` is actively maintained for backports, but if you need | |
| fixes in older releases, we are open to discussion. | |
| Security fixes are an exception: a maintainer may choose to backport a | |
| critical security fix to an older branch even after it would otherwise be | |
| closed. Discuss on the dev list or in a tracking issue before doing so. | |
| ## Backport Workflow | |
| The usual workflow is: | |
| 1. Fix on `main` first, and merge the fix via a normal PR workflow. | |
| 2. Cherry-pick the merged commit onto the release branch. | |
| 3. Open a backport PR targeting the release branch (examples below). | |
| - [Example backport PR] | |
| - [Additional backport PR example] | |
| ### Inputs | |
| To backport a change, gather the following information: | |
| - Target branch, such as `apache/branch-52` | |
| - The release tracking issue URL, such as https://github.com/apache/datafusion/issues/19692 | |
| - The original PR URL, such as https://github.com/apache/datafusion/pull/20192 | |
| - Optional explicit commit SHA to backport | |
| ### Apply the Backport | |
| Start from the target release branch, create a dedicated backport branch, and | |
| use `git cherry-pick`. For example, to backport PR #1234 to `branch-52` when | |
| the commit SHA is `abc123`, run: | |
| ```bash | |
| git checkout apache/branch-52 | |
| git checkout -b alamb/backport_1234 | |
| git cherry-pick abc123 | |
| ``` | |
| ### Test | |
| Run tests as described in the [testing documentation]. | |
| ### Open the PR | |
| Create a PR against the release branch, not `main`, and prefix it with | |
| `[branch-NN]` to show which release branch the backport targets. For example: | |
| - `[branch-52] fix: validate inter-file ordering in eq_properties() (#20329)` | |
| Use a PR description that links the tracking issue, original PR, and target | |
| branch, for example: | |
| ```markdown | |
| - Part of <tracking-issue-url> | |
| - Closes <backport-issue-url> on <branch-name> | |
| This PR: | |
| - Backports <original-pr-url> from @<author> to the <branch-name> line | |
| ``` | |
| [`main` branch]: https://github.com/apache/datafusion/tree/main | |
| [`branch-50`]: https://github.com/apache/datafusion/tree/branch-50 | |
| [the release process readme in `dev/release`]: https://github.com/apache/datafusion/blob/main/dev/release/README.md | |
| [datafusion releases tracking issue]: https://github.com/apache/datafusion/issues/19783 | |
| [release issue for 50.3.0]: https://github.com/apache/datafusion/issues/18072 | |
| [example backport pr]: https://github.com/apache/datafusion/pull/18131 | |
| [additional backport pr example]: https://github.com/apache/datafusion/pull/20792 | |
| [testing documentation]: testing.md | |
| [api health policy]: api-health.md | |
| [behavior changes]: #behavior-changes |