Django’s release process¶
Since version 1.0, Django’s release numbering works as follows:
- Versions are numbered in the form A.B or A.B.C.
- A is the major version number, which is only incremented for major changes to Django, and these changes are not necessarily backwards-compatible. That is, code you wrote for Django 1.6 may break when we release Django 2.0.
- B is the minor version number, which is incremented for large yet backwards compatible changes. Code written for Django 1.6 will continue to work under Django 1.7. Exceptions to this rule will be listed in the release notes.
- C is the micro version number, which is incremented for bug and security fixes. A new micro-release will be 100% backwards-compatible with the previous micro-release. The only exception is when a security issue can’t be fixed without breaking backwards-compatibility. If this happens, the release notes will provide detailed upgrade instructions.
- Before a new minor 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 our security policies.
- Major release
- Major releases (1.0, 2.0, etc.) will happen very infrequently (think “years”, not “months”), and may represent major, sweeping changes to Django.
- Minor release
Minor release (1.5, 1.6, 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.
A minor 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 1.5:
- Django 1.5 will contain a backwards-compatible replica of the function which will raise a PendingDeprecationWarning. This warning is silent by default; you can turn on display of these warnings with the -Wd option of Python.
- Django 1.6 will contain the backwards-compatible replica, but the warning will be promoted to a full-fledged DeprecationWarning. This warning is loud by default, and will likely be quite annoying.
- Django 1.7 will remove the feature outright.
- Micro release
Micro releases (1.5.1, 1.6.2, 1.6.1, etc.) will be issued as needed, often to fix security issues.
These releases will be 100% compatible with the associated minor release, unless this is impossible for security reasons. So the answer to “should I upgrade to the latest micro release?” will always be “yes.”
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 minor release, to be released as the next micro 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 minor release for bugs that would have prevented a release in the first place (release blockers).
Security fixes will be applied to the current master and the previous two minor releases.
Committers may choose to backport bugfixes at their own discretion, provided they do not introduce backwards incompatibilities.
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 1.6 and 1.7. At this point in time:
- Features will be added to development master, to be released as Django 1.7.
- Critical bug fixes will be applied to the stable/1.6.x branch, and released as 1.6.1, 1.6.2, etc.
- Security fixes will be applied to master, to the stable/1.6.x branch, and to the stable/1.5.x branch. They will trigger the release of 1.6.1, 1.5.1, etc.
- Documentation fixes will be applied to master, and, if easily backported, to the 1.6.x branch. Bugfixes may also be backported.
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 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.
Django uses a time-based release schedule, with minor (i.e. 1.6, 1.7, etc.) releases every nine months, or more, depending on features.
After each release, and after a suitable cooling-off period of a few weeks, the core development team 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 development we might schedule a longer period to allow for more ambitious work.
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.
After a minor release (e.g. 1.6), the previous release will go into bugfix mode.
A branch will be created of the form stable/1.5.x to track bugfixes to the previous release. 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.
How this all fits together¶
Let’s look at a hypothetical example for how this all first together. Imagine, if you will, a point about halfway between 1.5 and 1.6. At this point, development will be happening in a bunch of places:
- On master, development towards 1.6 proceeds with small additions, bugs fixes, etc. being checked in daily.
- On the branch stable/1.5.x, fixes for critical bugs found in the 1.5 release are checked in as needed. At some point, this branch will be released as “1.5.1”, “1.5.2”, etc.
- On the branch stable/1.4.x, security fixes are made if needed and released as “1.4.2”, “1.4.3”, etc.
- Development of major features is done in branches in forks of the main repository. These branches will be merged into master before “1.6 alpha 1”.