Xen Project Maintenance Releases

= Stable Maintenance Branches =
Each new Xen Project release X.Y.0 starts a new stable maintenance branch.
Each branch is maintained in the main xen.git repository in a stable-X.Y branch. See Xen Project Repositories for more information about the current branches.
Releases are intended to happen roughly every 4 months. The first
release on a stable branch is often sooner and as the branch reaches
the end of its life the interval may be longer.
In general XenProject.org supports stable branches for 18 months full support plus 18 months security fixes. When a new X.Y.0 release is made there is usually one more
release on the to-be-retired stable branch to mop up any loose patches
sitting in the repository at which point the branch is retired.
= Stable Branch Maintainer =
Each stable branch has a maintainer who is nominated/volunteers
according to the Maintainer Election process described in the
project governance
document. This will resulting in the MAINTAINERS file in the relevant
branch being patched to include the maintainer.
For the branches maintained by XenProject.org one of the regular xen-unstable
committers or maintainers would usually step up as maintainer. However
other community members can also step up to maintain a stable release,
typically once Xen.org no longer does so.
The stable branch maintainer is responsible for identifying suitable
candidates for inclusion in the stable branch both according to their
own judgment and by evaluating requests from the community (see
below).
= Stable Branch Patch Inclusion Policy =
No new development happens in the stable-X.Y branches, instead
changesets are backported from xen-unstable (AKA the master branch). Where this is not possible
(perhaps unstable has moved on such that the patch cannot be applied or
the approach used in unstable is otherwise not valid for the stable
branch) then a specific fix can be created for the stable branch.
However it is a requirement that the issue will always be fixed in
unstable first (this is to avoid regressions on the next major
release).
In general only bug fixes are accepted into stable branches and new
features are not normally accepted. (There can be exceptions, e.g. it
was agreed that 4.2.1 would take a more relaxed approach to features
which improved xl compatibility with xm). As time passes each stable
branch becomes more conservative and the barrier to accepting a patch
for backport becomes higher.
Changesets are included in the stable branch at the discretion of the
branch maintainer.
= Requesting A Backport =
As well as changesets identified by the branch maintainer as being suitable
for backport changes can also be nominated for inclusion in the stable
branch by making a request to the stable maintainer on the xen-devel mailing list
either by noting it as such in the submission of the original patch to
xen-unstable or by a subsequent explicit email to xen-devel.
Backport requests should always be copied to the relevant stable
maintainer. In addition as part of the the stable release process the
stable maintainer will send one or more requests to xen-devel
soliciting suggestions for patches which should be included.
Category:Development_Process
Category:Xen
Category:Project
Category:Developers