Contributing

Apache Paimon is developed by an open and friendly community. Everybody is cordially welcome to join the community and contribute to Apache Paimon. There are several ways to interact with the community and contribute to Paimon including asking questions, filing bug reports, proposing new features, joining discussions on the mailing lists, contributing code or documentation, improving website, testing release candidates and writing corresponding blog etc.

What do you want to do?

Contributing to Apache Paimon goes beyond writing code for the project. Below, we list different opportunities to help the project:

Code Contribution Guide

Apache Paimon is maintained, improved, and extended by code contributions of volunteers. We welcome contributions to Paimon.

Please feel free to ask questions at any time. Either send a mail to the Dev mailing list or comment on the issue you are working on.

1Discuss

Create an Issue or mailing list discussion and reach consensus

To request an issue, please note that it is not just a “please assign it to me”, you need to explain your understanding of the issue, and your design, and if possible, you need to provide your POC code.

2Implement

Create the Pull Request and the approach agreed upon in the issue.

1.Only create the PR if you are assigned to the issue. 2.Please associate an issue (if any), e.g. fix #123. 3.Please enable the actions of your own clone project.

3Review

Work with the reviewer.

1.Make sure no unrelated or unnecessary reformatting changes are included. 2.Please ensure that the test passing. 3.Please don’t resolve conversation.

4Merge

A committer of Paimon checks if the contribution fulfills the requirements and merges the code to the codebase.

Code Review Guide

Every review needs to check the following six aspects. We encourage to check these aspects in order, to avoid spending time on detailed code quality reviews when formal requirements are not met or there is no consensus in the community to accept the change.

1. Is the Contribution Well-Described?

Check whether the contribution is sufficiently well-described to support a good review. Trivial changes and fixes do not need a long description. If the implementation is exactly according to a prior discussion on issue or the development mailing list, only a short reference to that discussion is needed.

If the implementation is different from the agreed approach in the consensus discussion, a detailed description of the implementation is required for any further review of the contribution.

2. Does the Contribution Need Attention from some Specific Committers?

Some changes require attention and approval from specific committers.

If the pull request needs specific attention, one of the tagged committers/contributors should give the final approval.

3. Is the Overall Code Quality Good, Meeting Standard we Want to Maintain in Paimon?

• Does the code follow the right software engineering practices? Is the code correct, robust, maintainable, testable?
• Are the changes performance aware, when changing a performance sensitive part?
• Are the changes sufficiently covered by tests? Are the tests executing fast?
• If dependencies have been changed, were the NOTICE files updated?

Code guidelines can be found in the Flink Java Code Style and Quality Guide.

4. Are the documentation updated?

If the pull request introduces a new feature, the feature should be documented.

Become a Committer

How to become a committer

There is no strict protocol for becoming a committer. Candidates for new committers are typically people that are active contributors and community members. Candidates are suggested by current committers or PPMC members, and voted upon by the PPMC.

If you would like to become a committer, you should engage with the community and start contributing to Apache Paimon in any of the above ways. You might also want to talk to other committers and ask for their advice and guidance.

• Community contributions include helping to answer user questions on the mailing list, verifying release candidates, giving talks, organizing community events, and other forms of evangelism and community building. The “Apache Way” has a strong focus on the project community, and committers can be recognized for outstanding community contributions even without any code contributions.

• Code/technology contributions include contributed pull requests (patches), design discussions, reviews, testing, and other help in identifying and fixing bugs. Especially constructive and high quality design discussions, as well as helping other contributors, are strong indicators.

Identify promising candidates

While the prior points give ways to identify promising candidates, the following are “must haves” for any committer candidate:

• Being community minded: The candidate understands the meritocratic principles of community management. They do not always optimize for as much as possible personal contribution, but will help and empower others where it makes sense.

• We trust that a committer candidate will use their write access to the repositories responsibly, and if in doubt, conservatively. It is important that committers are aware of what they know and what they don’t know. In doubt, committers should ask for a second pair of eyes rather than commit to parts that they are not well familiar with.

• They have shown to be respectful towards other community members and constructive in discussions.