========================
Django's release process
========================

.. _official-releases:

Official releases
=================

Since version 1.0, Django's release numbering works as follows:

* Versions are numbered in the form ``A.B`` or ``A.B.C``.

* ``A.B`` is the *major version* number. Each version will be mostly backwards
  compatible with the previous release. Exceptions to this rule will be listed
  in the release notes. When ``B == 9``, the next major release will be
  ``A+1.0``. For example, Django 2.0 will follow Django 1.9. There won't be
  anything special about "dot zero" releases.

* ``C`` is the *minor version* number, which is incremented for bug and
  security fixes. A new minor release will be 100% backwards-compatible with
  the previous minor release. The only exception is when a security or data loss
  issue can't be fixed without breaking backwards-compatibility. If this
  happens, the release notes will provide detailed upgrade instructions.

* Before a new major release, we'll make alpha, beta, and release candidate
  releases. These are of the form ``A.B alpha/beta/rc N``, which means the
  ``Nth`` alpha/beta/release candidate of version ``A.B``.

In git, each Django release will have a tag indicating its version number,
signed with the Django release key. Additionally, each release series has its
own branch, called ``stable/A.B.x``, and bugfix/security releases will be
issued from those branches.

For more information about how the Django project issues new releases for
security purposes, please see :doc:`our security policies <security>`.

.. glossary::

  Major release
    Major releases (A.B, A.B+1, etc.) will happen roughly every nine months --
    see `release process`_, below for details. These releases will contain new
    features, improvements to existing features, and such.

    .. _internal-release-deprecation-policy:

    A major release may deprecate certain features from previous releases. If a
    feature is deprecated in version ``A.B``, it will continue to work in versions
    ``A.B`` and  ``A.B+1`` but raise warnings. It will be removed in version
    ``A.B+2``.

    So, for example, if we decided to start the deprecation of a function in
    Django 1.7:

    * Django 1.7 will contain a backwards-compatible replica of the function which
      will raise a ``RemovedInDjango19Warning``. This warning is silent by
      default; you can turn on display of these warnings with the ``-Wd`` option
      of Python.

    * Django 1.8 will still contain the backwards-compatible replica. This
      warning becomes *loud* by default, and will likely be quite annoying.

    * Django 1.9 will remove the feature outright.

  Minor release
    Minor releases (A.B.C, etc.) will be issued as needed, often to fix security
    issues.

    These releases will be 100% compatible with the associated major release,
    unless this is impossible for security reasons or to prevent data loss.
    So the answer to "should I upgrade to the latest minor release?" will always
    be "yes."

.. _backwards-compatibility-policy:

Supported versions
==================

At any moment in time, Django's developer team will support a set of releases to
varying levels:

* The current development master will get new features and bug fixes
  requiring major refactoring.

* Patches applied to the master branch must also be applied to the last major
  release, to be released as the next minor release, when they fix critical
  problems:

  * Security issues.

  * Data loss bugs.

  * Crashing bugs.

  * Major functionality bugs in newly-introduced features.

  The rule of thumb is that fixes will be backported to the last major release
  for bugs that would have prevented a release in the first place (release
  blockers).

* Security fixes and data loss bugs will be applied to the current master, the
  last two major releases, and the current :ref:`LTS release <lts-releases>`.

* Documentation fixes generally will be more freely backported to the last
  release branch. That's because it's highly advantageous to have the docs for
  the last release be up-to-date and correct, and the risk of introducing
  regressions is much less of a concern.

As a concrete example, consider a moment in time halfway between the release of
Django 1.7 and 1.8. At this point in time:

* Features will be added to development master, to be released as Django 1.8.

* Critical bug fixes will be applied to the ``stable/1.7.x`` branch, and
  released as 1.7.1, 1.7.2, etc.

* Security fixes and bug fixes for data loss issues will be applied to
  ``master`` and to the ``stable/1.7.x``, ``stable/1.6.x``, and
  ``stable/1.4.x`` (LTS) branches. They will trigger the release of ``1.7.1``,
  ``1.6.1``, ``1.4.1``, etc.

* Documentation fixes will be applied to master, and, if easily backported, to
  the ``1.7.x`` and ``1.6.x`` branches.

.. _lts-releases:

Long-term support (LTS) releases
================================

Additionally, the Django team will occasionally designate certain releases
to be "Long-term support" (LTS) releases. LTS releases will get security and
data loss fixes applied for a guaranteed period of time, typically 3+ years,
regardless of the pace of releases afterwards.

The follow releases have been designated for long-term support:

* Django 1.8, supported for at least 3 years after its release (scheduled for
  April 2015).
* Django 1.4, supported for 6 months after the release of Django 1.8. As
  Django 1.8 is scheduled to be released around April 2015, support for 1.4
  will end around October 2015.

.. _release-process:

Release process
===============

Django uses a time-based release schedule, with major (i.e. 1.8, 1.9, 2.0,
etc.) releases every nine months, or more, depending on features.

After each release, and after a suitable cooling-off period of a few weeks,
core developers will examine the landscape and announce a timeline for the
next release. Most releases will be scheduled in the 6-9 month range, but if
we have bigger features to develop we might schedule a longer period to
allow for more ambitious work.

Release cycle
-------------

Each release cycle will be split into three periods, each lasting roughly
one-third of the cycle:

Phase one: feature proposal
~~~~~~~~~~~~~~~~~~~~~~~~~~~

The first phase of the release process will be devoted to figuring out what
features to include in the next version. This should include a good deal of
preliminary work on those features -- working code trumps grand design.

At the end of part one, the core developers will propose a feature list for the
upcoming release. This will be broken into:

* "Must-have": critical features that will delay the release if not finished
* "Maybe" features: that will be pushed to the next release if not finished
* "Not going to happen": features explicitly deferred to a later release.

Anything that hasn't got at least some work done by the end of the first third
isn't eligible for the next release; a design alone isn't sufficient.

Phase two: development
~~~~~~~~~~~~~~~~~~~~~~

The second third of the release schedule is the "heads-down" working period.
Using the roadmap produced at the end of phase one, we'll all work very hard to
get everything on it done.

Longer release schedules will likely spend more than a third of the time in this
phase.

At the end of phase two, any unfinished "maybe" features will be postponed until
the next release. Though it shouldn't happen, any "must-have" features will
extend phase two, and thus postpone the final release.

Phase two will culminate with an alpha release. At this point, the
``stable/A.B.x`` branch will be forked from ``master``.

Phase three: bugfixes
~~~~~~~~~~~~~~~~~~~~~

The last third of a release cycle is spent fixing bugs -- no new features will
be accepted during this time. We'll try to release a beta release after one
month and a release candidate after two months.

The release candidate marks the string freeze, and it happens at least two
weeks before the final release. After this point, new translatable strings
must not be added.

During this phase, committers will be more and more conservative with
backports, to avoid introducing regressions. After the release candidate, only
release blockers and documentation fixes should be backported.

In parallel to this phase, ``master`` can receive new features, to be released
in the ``A.B+1`` cycle.

Bug-fix releases
----------------

After a major release (e.g. A.B), the previous release will go into bugfix
mode.

The branch for the previous major release (e.g. ``stable/A.B-1.x``) will include
bugfixes. Critical bugs fixed on master must *also* be fixed on the bugfix
branch; this means that commits need to cleanly separate bug fixes from feature
additions. The developer who commits a fix to master will be responsible for
also applying the fix to the current bugfix branch.
