We prefer to receive code contributions in the form of github pull requests. When you submit a pull request, there are a few things to keep in mind. Please ensure code changes:

• Are Small. Submissions should be for a single feature/bugfix, don't group submissions together.
• Are Green. All code that is committed to Geode should pass all PR checks (you can also run ./gradlew precheckin but this can take many hours).
• Have a JIRA. Changes should be associated with a ticket in jira.  The initial commit should begin with <ticket><colon><space> followed by a concise summary line, then additional lines detailing what is being changed and why (see Commit Message Format).
• Are Discussed. Changes that affect public API or introduce new features must be discussed on the mailing list. Geode is a mature product with many active users in production, so new APIs or features need to meet a high standard of quality. If a feature can be developed as an extension of Geode that may be more desirable - see Public APIs.
• Have a backwards compatible API. All changes to the public API must be backward-compatible (with the exception of removing deprecated features, but this requires discussion).
• Have backwards compatible messaging. Geode supports rolling upgrades on a live system. Any changes must be backward-compatible with previous versions, including but not limited to messaging, disk persistence, and algorithmic traits. Geode has a framework for backward-compatible serialization - see Managing backward-compatibility.
• Follow Style Guidelines. Code should adhere to the Code Style Guide.
• Have tests. New features must be accompanied by tests. Bug fixes should also include a test for the bug. See Writing tests.
• Have few dependencies. Avoid introducing new library dependencies when possible. Licenses for third-party dependencies must conform to Apache requirements.
• Are Safe. Geode is a heavily-concurrent product. Code changes should be carefully considered with regard to thread safety and distributed system safety.
• Are Secure. Geode should be secure by default.  Don't introduce new vulnerabilities or unsecured backdoors.

It's best to start small with bug fixes or smaller features. Please feel free to discuss things and ask for help on the mailing list if you are interested in contributing.

Changing the Public API

If you making changes to the public API, make sure dev@geode.apache.org is aware that the changes will affect the public API by sending an email with [DISCUSS] in the subject to describe your changes.  Due to the large number of Geode users, we try to avoid breaking compatibility between versions.

Backwards Compatibility

In general, nothing can be removed or modified in way that is not backward-compatible. If something is deprecated, it can be removed in the next major release, after discussion on the dev list.  Backwards compatibility affects API's, client applications, and WAN clusters.  Support for rolling upgrades is another important consideration.

Javadocs and @since tags

All public and internal APIs should have useful javadocs. For all public 
APIs (anything not in /internal/), new additions to the javadocs 
should include a @since tag to let the users know when the feature was 
added. Eg

Any feature which is deprecated should specify a link to the new alternative.

Use of hardcoded "/" in region paths or names

When writing code in a module which has a dependency on geode-core, Region.SEPARATOR and Region.SEPARATOR_CHAR constants should be used instead of hardcoded "/" characters in region names and paths.