Apache ZooKeeper Project Bylaws

This is version 1 of the bylaws.


This document defines the bylaws under which the Apache ZooKeeper
project operates. It defines the roles and responsibilities of the
project, who may vote, how voting works, how conflicts are resolved, etc.

ZooKeeper is a project of the Apache Software Foundation The foundation
holds the copyright on Apache code including the code in the ZooKeeper
codebase. The foundation FAQ explains the operation and background of
the foundation.

ZooKeeper is typical of Apache projects in that it operates under a set
of principles, known collectively as the Apache Way. If you are new to
Apache development, please refer to the Incubator project for more
information on how Apache projects operate.

Roles and Responsibilities

Apache projects define a set of roles with associated rights and
responsibilities. These roles govern what tasks an individual may
perform within the project. The roles are defined in the following sections.


The most important participants in the project are people who use our
software. The majority of our contributors start out as users and guide
their development efforts from the user's perspective.

Users contribute to the Apache projects by providing feedback to
contributors in the form of bug reports and feature suggestions. As
well, users participate in the Apache community by helping other users
on mailing lists and user support forums.


All of the volunteers who are contributing time, code, documentation, or
resources to the ZooKeeper Project. A contributor that makes sustained,
welcome contributions to the project may be invited to become a
committer, though the exact timing of such invitations depends on many


The project's committers are responsible for the project's technical
management. Committers have access to a specified set of subproject's
repositories. Committers on subprojects may cast binding
votes on any technical discussion regarding that subproject.

Committer access is by invitation only and must be approved by lazy
consensus of the active PMC members. A Committer is considered emeritus
by his or her own declaration or by not reviewing patches or commiting
patches to the project for over six months. An emeritus committer may
request reinstatement of commit access from the PMC which must be
approved by lazy consensus of the active PMC members.

Commit access can be revoked by a unanimous vote of all the active PMC
members (except the committer in question if he or she is also a PMC

All Apache committers are required to have a signed Contributor License Agreement
on file with the Apache Software Foundation. There is a
Committer FAQ which provides more details on the requirements for

A committer who makes a sustained contribution to the project may be
invited to become a member of the PMC. The form of contribution is not
limited to code. It can also include code review, helping out users on
the mailing lists, documentation, etc.

Project Management Committee

The PMC is responsible to the board and the ASF for the management and
oversight of the Apache ZooKeeper codebase. The responsibilities of the
PMC include:

  • Deciding what is distributed as products of the Apache ZooKeeper
    project. In particular all releases must be approved by the PMC.
  • Maintaining the project's shared resources, including the codebase
    repository, mailing lists, websites.
  • Speaking on behalf of the project.
  • Resolving license disputes regarding products of the project.
  • Nominating new PMC members and committers.
  • Maintaining these bylaws and other guidelines of the project.
  • Membership of the PMC is by invitation only and must be approved by a
    lazy consensus of active PMC members. A PMC member is considered
    emeritus by his or her own declaration or by not contributing in any
    form to the project for over six months. An emeritus member may request
    reinstatement to the PMC, which must be approved by a lazy consensus of
    active PMC members.

Membership of the PMC can be revoked by an unanimous vote of all the
active PMC members other than the member in question.

The chair of the PMC is appointed by the ASF board. The chair is an
office holder of the Apache Software Foundation (Vice President, Apache
ZooKeeper) and has primary responsibility to the board for the
management of the projects within the scope of the ZooKeeper PMC. The
chair reports to the board quarterly on developments within the
ZooKeeper project.

When the current chair of the PMC resigns, the PMC votes to recommend a
new chair using lazy consensus, but the decision must be ratified by the
Apache board.

Decision Making

Within the ZooKeeper project, different types of decisions require
different forms of approval. For example, the previous section describes
several decisions which require 'lazy consensus' approval. This section
defines how voting is performed, the types of approvals, and which types
of decision require which type of approval.


Decisions regarding the project are made by votes on the primary project
development mailing list dev@zookeeper.apache.org. Where necessary, PMC
voting may take place on the private ZooKeeper PMC mailing list
private@zookeeper.apache.org. Votes are clearly indicated by subject
line starting with [VOTE]. Votes may contain multiple items for approval
and these should be clearly separated. Voting is carried out by replying
to the vote mail. Voting may take four flavors.

+1'Yes,' 'Agree,' or 'the action should be performed.' In general,
this vote also indicates a willingness on the behalf of the voter in
'making it happen'.
+0This vote indicates a willingness for the action under
consideration to go ahead. The voter, however will not be able to help.
-0This vote indicates that the voter does not, in general, agree
with the proposed action but is not concerned enough to prevent the
action going ahead.
-1This is a negative vote. On issues where consensus is required,
this vote counts as a veto. All vetoes must contain an explanation of
why the veto is appropriate. Vetoes with no explanation are void. It may
also be appropriate for a -1 vote to include an alternative course of

All participants in the ZooKeeper project are encouraged to show their
agreement with or against a particular action by voting. For technical
decisions, only the votes of active committers are binding. Non binding
votes are still useful for those with binding votes to understand the
perception of an action in the wider ZooKeeper community. For PMC
decisions, only the votes of PMC members are binding.

Voting can also be applied to changes already made to the ZooKeeper
codebase. These typically take the form of a veto (-1) in reply to the
commit message sent when the commit is made. Note that this should be a
rare occurrence. All efforts should be made to discuss issues when they
are still patches before the code is committed.


There are the types of approvals that can be sought. Different actions
require different types of approvals.

Approval TypeDefinition
ConsensusFor this to pass, all voters with binding votes must
vote and there can be no binding vetoes (-1). Consensus votes are rarely
required due to the impracticality of getting all eligible voters to
cast a vote.
Lazy ConsensusLazy consensus requires 3 binding +1 votes and no
binding vetoes.
Lazy MajorityA lazy majority vote requires 3 binding +1 votes and
more binding +1 votes that -1 votes.
Lazy ApprovalAn action with lazy approval is implicitly allowed
unless a -1 vote is received, at which time, depending on the type of
action, either lazy majority or lazy consensus approval must be obtained.
2/3 MajoritySome actions require a 2/3 majority of active committers
or PMC members to pass. Such actions typically affect the foundation of
the project (e.g. adopting a new codebase to replace an existing
product). The higher threshold is designed to ensure such changes are
strongly supported. To pass this vote requires at least 2/3 of binding
vote holders to vote +1.


A valid, binding veto cannot be overruled. If a veto is cast, it must
be accompanied by a valid reason explaining the reasons for the
veto. The validity of a veto, if challenged, can be confirmed by
anyone who has a binding vote. This does not necessarily signify
agreement with the veto - merely that the veto is valid.

If you disagree with a valid veto, you must lobby the person casting the
veto to withdraw his or her veto. If a veto is not withdrawn, the action
that has been vetoed must be reversed in a timely manner.


This section describes the various actions which are undertaken within
the project, the corresponding approval required for that action and
those who have binding votes over the action. It also specifies the
minimum length of time that a vote must remain open, measured in
business days. In general votes should not be called at times when it is
known that interested members of the project will be unavailable.

ActionDescriptionApprovalBinding VotesMinimum Length (days)
Code ChangeA change made to a codebase of the project and committed
by a committer. This includes source code, documentation, website
content, etc.
Lazy approval (not counting the vote of the
contributor), moving to lazy majority if a -1 is received
Release PlanDefines the timetable and actions for a release. The
plan also nominates a Release Manager.
Lazy majorityActive
Product ReleaseWhen a release of one of the project's products is
ready, a vote is required to accept the release as an official release
of the project.
Lazy MajorityActive PMC members3
Adoption of New CodebaseWhen the codebase for an existing, released
product is to be replaced with an alternative codebase. If such a vote
fails to gain approval, the existing code base will continue. This also
covers the creation of new sub-projects within the project.
Active PMC members6
New Committer or reinstatementWhen a new committer is proposed for
the project.
Lazy consensusActive PMC members3
New PMC Member or reinstatementWhen a committer is proposed for the
Lazy consensusActive PMC members3
Committer RemovalWhen removal of commit privileges is sought. Note:
Such actions will also be referred to the ASF board by the PMC chair.
ConsensusActive PMC members (excluding the committer in question
if a member of the PMC).
PMC Member RemovalWhen removal of a PMC member is sought. Note: Such
actions will also be referred to the ASF board by the PMC chair.
ConsensusActive PMC members (excluding the member in question).6
Modifying BylawsModifying this document.2/3 majorityActive
PMC members