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diff --git a/doc/dev/development-workflow.rst b/doc/dev/development-workflow.rst new file mode 100644 index 00000000..dfcab929 --- /dev/null +++ b/doc/dev/development-workflow.rst @@ -0,0 +1,248 @@ +===================== +Development workflows +===================== + +This page explains the workflows a developer is expected to follow to +implement the goals that are part of the Ceph release cycle. It does not +go into technical details and is designed to provide a high level view +instead. Each chapter is about a given goal such as ``Merging bug +fixes or features`` or ``Publishing point releases and backporting``. + +A key aspect of all workflows is that none of them blocks another. For +instance, a bug fix can be backported and merged to a stable branch +while the next point release is being published. For that specific +example to work, a branch should be created to avoid any +interference. In practice it is not necessary for Ceph because: + +* there are few people involved +* the frequency of backports is not too high +* the reviewers, who know a release is being published, are unlikely + to merge anything that may cause issues + +This ad-hoc approach implies the workflows are changed on a regular +basis to adapt. For instance, ``quality engineers`` were not involved +in the workflow to publish ``dumpling`` point releases. The number of +commits being backported to ``firefly`` made it impractical for developers +tasked to write code or fix bugs to also run and verify the full suite +of integration tests. Inserting ``quality engineers`` makes it +possible for someone to participate in the workflow by analyzing test +results. + +The workflows are not enforced when they impose an overhead that does +not make sense. For instance, if the release notes for a point release +were not written prior to checking all integration tests, they can be +committed to the stable branch and the result sent for publication +without going through another run of integration tests. + +Release Cycle +============= + +:: + + Ceph hammer infernalis + Developer CDS CDS + Summit | | + | | + development | | + release | v0.88 v0.89 v0.90 ... | v9.0.0 + --v--^----^--v---^------^--v- ---v----^----^--- 2015 + | | | | + stable giant | | hammer + release v0.87 | | v0.94 + | | + point firefly dumpling + release v0.80.8 v0.67.12 + + +Four times a year, the development roadmap is discussed online during +the `Ceph Developer Summit <http://tracker.ceph.com/projects/ceph/wiki/Planning#Ceph-Developer-Summit>`_. A +new stable release (hammer, infernalis, jewel ...) is published at the same +frequency. Every other release (firefly, hammer, jewel...) is a `Long Term +Stable (LTS) <../../releases>`_. See `Understanding the release cycle +<../../releases#understanding-the-release-cycle>`_ for more information. + +Merging bug fixes or features +============================= + +The development branch is ``master`` and the workflow followed by all +developers can be summarized as follows: + +* The developer prepares a series of commits +* The developer submits the series of commits via a pull request +* A reviewer is assigned the pull request +* When the pull request looks good to the reviewer, it is merged into + an integration branch by the tester +* After a successful run of integration tests, the pull request is + merged by the tester + +The ``developer`` is the author of a series of commits. The +``reviewer`` is responsible for providing feedback to the developer on +a regular basis and the developer is invited to ping the reviewer if +nothing happened after a week. After the ``reviewer`` is satisfied +with the pull request, (s)he passes it to the ``tester``. The +``tester`` is responsible for running teuthology integration tests on +the pull request. If nothing happens within a month the ``reviewer`` is +invited to ping the ``tester``. + +Resolving bug reports and implementing features +=============================================== + +All bug reports and feature requests are in the `issue tracker +<http://tracker.ceph.com>`_ and the workflow can be summarized as +follows: + +* The reporter creates the issue with priority ``Normal`` +* A developer may pick the issue right away +* During a bi-weekly bug scrub, the team goes over all new issue and + assign them a priority +* The bugs with higher priority are worked on first + +Each ``team`` is responsible for a project, managed by :ref:`leads <governance>`. + +The ``developer`` assigned to an issue is responsible for it. The +status of an open issue can be: + +* ``New``: it is unclear if the issue needs work. +* ``Verified``: the bug can be reproduced or showed up multiple times +* ``In Progress``: the developer is working on it this week +* ``Pending Backport``: the fix needs to be backported to the stable + releases listed in the backport field + +For each ``Pending Backport`` issue, there exists at least one issue +in the ``Backport`` tracker to record the work done to cherry pick the +necessary commits from the master branch to the target stable branch. +See `the backporter manual +<http://tracker.ceph.com/projects/ceph-releases/wiki/HOWTO>`_ for more +information. + +Running and interpreting teuthology integration tests +===================================================== + +The :doc:`/dev/sepia` runs `teuthology +<https://github.com/ceph/teuthology/>`_ integration tests `on a regular basis <http://tracker.ceph.com/projects/ceph-releases/wiki/HOWTO_monitor_the_automated_tests_AKA_nightlies#Automated-tests-AKA-nightlies>`_ and the +results are posted on `pulpito <http://pulpito.ceph.com/>`_ and the +`ceph-qa mailing list <https://ceph.com/irc/>`_. + +* The job failures are `analyzed by quality engineers and developers + <http://tracker.ceph.com/projects/ceph-releases/wiki/HOWTO_monitor_the_automated_tests_AKA_nightlies#List-of-suites-and-watchers>`_ +* If the cause is environmental (e.g. network connectivity), an issue + is created in the `sepia lab project + <http://tracker.ceph.com/projects/lab/issues/new>`_ +* If the bug is known, a pulpito URL to the failed job is added to the issue +* If the bug is new, an issue is created + +The ``quality engineer`` is either a developer or a member of the QE +team. There is at least one integration test suite per project: + +* `rgw <https://github.com/ceph/ceph/tree/master/qa/suites/rgw>`_ suite +* `CephFS <https://github.com/ceph/ceph/tree/master/qa/suites/fs>`_ suite +* `rados <https://github.com/ceph/ceph/tree/master/qa/suites/rados>`_ suite +* `rbd <https://github.com/ceph/ceph/tree/master/qa/suites/rbd>`_ suite + +and many others such as + +* `upgrade <https://github.com/ceph/ceph/tree/master/qa/suites/upgrade>`_ suites +* `power-cyle <https://github.com/ceph/ceph/tree/master/qa/suites/powercycle>`_ suite +* ... + +Preparing a new release +======================= + +A release is prepared in a dedicated branch, different from the +``master`` branch. + +* For a stable releases it is the branch matching the release code + name (dumpling, firefly, etc.) +* For a development release it is the ``next`` branch + +The workflow expected of all developers to stabilize the release +candidate is the same as the normal development workflow with the +following differences: + +* The pull requests must target the stable branch or next instead of + master +* The reviewer rejects pull requests that are not bug fixes +* The ``Backport`` issues matching a teuthology test failure and set + with priority ``Urgent`` must be fixed before the release + +Cutting a new stable release +============================ + +A new stable release can be cut when: + +* all ``Backport`` issues with priority ``Urgent`` are fixed +* integration and upgrade tests run successfully + +Publishing a new stable release implies a risk of regression or +discovering new bugs during the upgrade, no matter how carefully it is +tested. The decision to cut a release must take this into account: it +may not be wise to publish a stable release that only fixes a few +minor bugs. For instance if only one commit has been backported to a +stable release that is not a LTS, it is better to wait until there are +more. + +When a stable release is to be retired, it may be safer to +recommend an upgrade to the next LTS release instead of +proposing a new point release to fix a problem. For instance, the +``dumpling`` v0.67.11 release has bugs related to backfilling which have +been fixed in ``firefly`` v0.80.x. A backport fixing these backfilling +bugs has been tested in the draft point release ``dumpling`` v0.67.12 but +they are large enough to introduce a risk of regression. As ``dumpling`` +is to be retired, users suffering from this bug can +upgrade to ``firefly`` to fix it. Unless users manifest themselves and ask +for ``dumpling`` v0.67.12, this draft release may never be published. + +* The ``Ceph lead`` decides a new stable release must be published +* The ``release master`` gets approval from all leads +* The ``release master`` writes and commits the release notes +* The ``release master`` informs the ``quality engineer`` that the + branch is ready for testing +* The ``quality engineer`` runs additional integration tests +* If the ``quality engineer`` discovers new bugs that require an + ``Urgent Backport``, the release goes back to being prepared, it + was not ready after all +* The ``quality engineer`` informs the ``publisher`` that the branch + is ready for release +* The ``publisher`` `creates the packages and sets the release tag + <../release-process>`_ + +The person responsible for each role is: + +* Sage Weil is the ``Ceph lead`` +* Sage Weil is the ``release master`` for major stable releases + (``firefly`` 0.80, ``hammer`` 0.94 etc.) +* Loic Dachary is the ``release master`` for stable point releases + (``firefly`` 0.80.10, ``hammer`` 0.94.1 etc.) +* Yuri Weinstein is the ``quality engineer`` +* Alfredo Deza is the ``publisher`` + +Cutting a new development release +================================= + +The publication workflow of a development release is the same as +preparing a new release and cutting it, with the following +differences: + +* The ``next`` branch is reset to the tip of ``master`` after + publication +* The ``quality engineer`` is not required to run additional tests, + the ``release master`` directly informs the ``publisher`` that the + release is ready to be published. + +Publishing point releases and backporting +========================================= + +The publication workflow of the point releases is the same as +preparing a new release and cutting it, with the following +differences: + +* The ``backport`` field of each issue contains the code name of the + stable release +* There is exactly one issue in the ``Backport`` tracker for each + stable release to which the issue is backported +* All commits are cherry-picked with ``git cherry-pick -x`` to + reference the original commit + +See `the backporter manual +<http://tracker.ceph.com/projects/ceph-releases/wiki/HOWTO>`_ for more +information. |