Project Governance / Engineering Steering Committee

The Gerrit project has an engineering steering committee (ESC) that is in charge of:

  • Gerrit core (the gerrit project) and the core plugins

  • defining the project vision and the project scope

  • maintaining a roadmap, a release plan and a prioritized backlog

  • ensuring timely design reviews

  • ensuring that new features are compatible with the project vision and are well aligned with other features (give feedback on new design docs within 14 calendar days)

  • approving/rejecting designs, vetoing new features

  • assigning mentors for approved features

  • accepting new plugins as core plugins

  • making changes to the project governance process and the contribution processes

The steering committee has 5 members:

  • 3 Googlers that are appointed by Google

  • 2 non-Google maintainers, elected by non-Google maintainers for the period of 1 year (see below)

Refer to the project homepage for the list of current committee members.

The steering committee should act in the interest of the Gerrit project and the whole Gerrit community.

For decisions, consensus between steering committee members and all other maintainers is desired. If consensus cannot be reached, decisions can also be made by simple majority in the steering committee (should be applied only in exceptional situations).

The steering committee is empowered to overrule positive/negative votes from individual maintainers, but should do so only in exceptional situations after attempts to reach consensus have failed.

As an integral part of the Gerrit community, the steering committee is committed to transparency and to answering incoming requests in a timely manner.

Election of non-Google steering committee members

The election of the non-Google steering committee members happens once a year in May. Non-Google maintainers can nominate themselves by posting an informal application on the non-public maintainers mailing list by end of April (deadline for 2019 is Mon 13th of May). By applying to be steering committee member, the candidate confirms to be able to dedicate the time that is needed to fulfill this role (also see steering committee member).

Each non-Google maintainer can vote for 2 candidates. The voting happens by posting on the maintainer mailing list. The voting period is 14 calendar days from the nomination deadline (except for 2019, where the initial steering committee should be confirmed during the Munich hackathon, the voting period goes from 14th May to 16th May).

Google maintainers do not take part in this vote, because Google already has dedicated seats in the steering committee (see section steering committee).

Contribution Process

See here.

Design Doc Review

See here.

Semantic versioning

Gerrit follows a light semantic versioning scheme MAJOR.MINOR[.PATCH[.HOTFIX]] format:

  • MAJOR is incremented when there are substantial incompatible changes and/or new features in Gerrit.

  • MINOR is incremented when there are changes that are typically backward compatible with the earlier minor version. Features can be removed following the feature deprecation process. Dependencies can be upgraded according to the libraries upgrade policy.

  • PATCH is incremented when there are backward-compatible bug fixes in Gerrit or its dependencies. When PATCH is zero, it can be omitted.

  • HOTFIX is present only when immediately after a patch release, some urgent fixes in the code or the packaging format are required but do not justify a new patch release.

For every MAJOR.MINOR release there is an associated stable branch that follows well defined rules of development.

Within a stable branch, there are multiple MAJOR.MINOR.PATCH tags created associated to the bug-fix releases of that stable release.


  • Gerrit v3.0.0 contains breaking incompatible changes in the functionality because the ReviewDb storage has been totally removed.

  • Gerrit v2.15 contains brand-new features like NoteDb, however, still supports the existing ReviewDb storage for changes and thus is considered a minor release.

  • Gerrit v2.14.20 is the 20th patch-release of the stable Gerrit v2.14.* and thus does not contain new features but only bug-fixes.

Development in stable branches

As their name suggests stable branches are intended to be stable. This means that generally only bug-fixes should be done on stable branches, however this is not strictly enforced and exceptions may apply:

  • When a stable branch is initially created to prepare a new release the Gerrit community discusses on the mailing list if there are pending features which should still make it into the release. Those features are blocking the release and should be implemented on the stable branch before the first release candidate is created.

  • To stabilize the code before doing a major release several release candidates are created. Once the first release candidate was done no more features should be accepted on the stable branch. If more features are found to be required they should be discussed with the steering committee and should only be allowed if the risk of breaking things is considered to be low.

  • Once a major release is done only bug-fixes and documentation updates should be done on the stable branch. These updates will be included in the next minor release.

  • For minor releases new features could be acceptable if the following conditions are met:

    • they are result of a new feature introduced through a merge of an earlier stable branch

    • they are justified for completing, extending or fixing an existing feature

    • does not involve API, user-interface changes or data migrations

    • is backward compatible with all existing features

    • the parts of the code in common with existing features are properly covered by end-to-end tests

    • is important to the Gerrit community and no Gerrit maintainers have raised objections.

  • In cases of doubt or conflicting opinions on new features, it’s the responsibility of the steering committee to evaluate the risk of new features and make a decision based on these rules and opinions from the Gerrit community.

  • The older a stable branch is the more stable it should be. This means old stable branches should only receive bug-fixes that are either important or low risk. Security fixes, including security updates for third party dependencies, are always considered as important and hence can always be done on stable branches.


  • Gerrit v3.0.0-rc1 and v3.0.0-rc2 may contain new features and API changes without notice, even if they are both cut on the same stable-3.0 branch.

  • Gerrit v2.14.8 introduced the support for ElasticSearch as a new feature. This was an exception agreed amongst the Gerrit maintainers, did not touch the Lucene indexing code-base, was supported by container-based E2E tests and represents a completion of an high-level feature.

Backporting to stable branches

From time to time bug fix releases are made for existing stable branches.

Developers concerned with stable branches are encouraged to backport or push fixes to these branches, even if no new release is planned. Backporting features is only possible in compliance with the rules above.

Fixes that are known to be needed for a particular release should be pushed for review on that release’s stable branch. They will then be included into the master branch when the stable branch is merged back.

Upgrading Libraries

Changes that add new libraries or upgrade existing libraries require an approval on the Library-Compliance label. For an approval the following things are checked:

  • The library has a license that is suitable for use within Gerrit.

  • If the library is used within Google, the version of the library must be compatible with the version that is used at Google.

Only maintainers from Google can vote on the Library-Compliance label.

Gerrit’s library dependencies should only be upgraded if the new version contains something we need in Gerrit. This includes new features, API changes as well as bug or security fixes. An exception to this rule is that right after a new Gerrit release was branched off, all libraries should be upgraded to the latest version to prevent Gerrit from falling behind. Doing those upgrades should conclude at the latest two months after the branch was cut. This should happen on the master branch to ensure that they are vetted long enough before they go into a release and we can be sure that the update doesn’t introduce a regression.

Deprecating features

Gerrit should be as stable as possible and we aim to add only features that last. However, sometimes we are required to deprecate and remove features to be able to move forward with the project and keep the code-base clean. The following process should serve as a guideline on how to deprecate functionality in Gerrit. Its purpose is that we have a structured process for deprecation that users, administrators and developers can agree and rely on.

General process:

  • Make sure that the feature (e.g. a field on the API) is not needed anymore or blocks further development or improvement. If in doubt, consult the mailing list.

  • If you can provide a schema migration that moves users to a comparable feature, do so and stop here.

  • Mark the feature as deprecated in the documentation and release notes.

  • If possible, mark the feature deprecated in any user-visible interface. For example, if you are deprecating a Git push option, add a message to the Git response if the user provided the option informing them about deprecation.

  • Annotate the code with @Deprecated and @RemoveAfter(x.xx) if applicable. Alternatively, use // DEPRECATED, remove after x.xx (where x.xx is the version number that has to be branched off before removing the feature)

  • Gate the feature behind a config that is off by default (forcing admins to turn the deprecated feature on explicitly).

  • After the next release was branched off, remove any code that backed the feature.

You can optionally consult the mailing list to ask if there are users of the feature you wish to deprecate. If there are no major users, you can remove the feature without following this process and without the grace period of one release.