doc: add guidelines on stable and lts releases

Add document explaining the current Stable and LTS process.

Signed-off-by: John McNamara <john.mcnamara@intel.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>

diff --git a/doc/guides/contributing/index.rst b/doc/guides/contributing/index.rst
index f6af317..329b678 100644 (file)
--- a/doc/guides/contributing/index.rst
+++ b/doc/guides/contributing/index.rst
@@ -10,4 +10,5 @@ Contributor's Guidelines
     versioning
     documentation
     patches
+    stable
     cheatsheet

diff --git a/doc/guides/contributing/stable.rst b/doc/guides/contributing/stable.rst
new file mode 100644 (file)
index 0000000..d52ec47
--- /dev/null
+++ b/doc/guides/contributing/stable.rst
@@ -0,0 +1,99 @@
+.. stable_lts_releases:
+
+DPDK Stable Releases and Long Term Support
+==========================================
+
+This section sets out the guidelines for the DPDK Stable Releases and the DPDK
+Long Term Support releases (LTS).
+
+
+Introduction
+------------
+
+The purpose of the DPDK Stable Releases is to maintain releases of DPDK with
+backported fixes over an extended period of time. This provides downstream
+consumers of DPDK with a stable target on which to base applications or
+packages.
+
+The Long Term Support release (LTS) is a designation applied to a Stable
+Release to indicate longer term support.
+
+
+Stable Releases
+---------------
+
+Any major release of DPDK can be designated as a Stable Release if a
+maintainer volunteers to maintain it.
+
+A Stable Release is used to backport fixes from an ``N`` release back to an
+``N-1`` release, for example, from 16.11 to 16.07.
+
+The duration of a stable is one complete release cycle (3 months). It can be
+longer, up to 1 year, if a maintainer continues to support the stable branch,
+or if users supply backported fixes, however the explicit commitment should be
+for one release cycle.
+
+The release cadence is determined by the maintainer based on the number of
+bugfixes and the criticality of the bugs. Releases should be coordinated with
+the validation engineers to ensure that a tagged release has been tested.
+
+
+LTS Release
+-----------
+
+A stable release can be designated as an LTS release based on community
+agreement and a commitment from a maintainer. An LTS release will have a
+maintenance duration of 2 years.
+
+The current DPDK LTS release is 16.11.
+
+It is anticipated that there will be at least 4 releases per year of the LTS
+or approximately 1 every 3 months. However, the cadence can be shorter or
+longer depending on the number and criticality of the backported
+fixes. Releases should be coordinated with the validation engineers to ensure
+that a tagged release has been tested.
+
+
+What changes should be backported
+---------------------------------
+
+Backporting should be limited to bug fixes.
+
+Features should not be backported to stable releases. It may be acceptable, in
+limited cases, to back port features for the LTS release where:
+
+* There is a justifiable use case (for example a new PMD).
+* The change is non-invasive.
+* The work of preparing the backport is done by the proposer.
+* There is support within the community.
+
+
+The Stable Mailing List
+-----------------------
+
+The Stable and LTS release are coordinated on the stable@dpdk.org mailing
+list.
+
+All fix patches to the master branch that are candidates for backporting
+should also be CCed to the `stable@dpdk.org <http://dpdk.org/ml/listinfo/stable>`_
+mailing list.
+
+
+Releasing
+---------
+
+A Stable Release will be released by:
+
+* Tagging the release with YY.MM.n (year, month, number).
+* Uploading a tarball of the release to dpdk.org.
+* Sending an announcement to the `announce@dpdk.org <http://dpdk.org/ml/listinfo/announce>`_
+  list.
+
+Stable releases are available on the `dpdk.org download page <http://dpdk.org/download>`_.
+
+
+ABI
+---
+
+The Stable Release should not be seen as a way of breaking or circumventing
+the DPDK ABI policy.