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← Revision 30 as of 2010-11-08 18:30:41 → ⇥
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Editor: lifeless
Comment: update
Deletions are marked like this. Additions are marked like this.
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This is a proposal of how a developer branch flows through the different production branches we have, after the developer branch is ready for landing. This is a description of how a developer branch flows through the different
'official' branches we have, after the developer branch is ready for landing.
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To summarize, branches that contain db changes always get landed to the `db`
branch. Other changes get landed to the `edge` branch, although branches that are part of a larger features (consisting of multiple branches) get landed to edge through an integration branch for that feature.		 = Merge Workflow =
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The landed revision stays in the `edge` branch until it has been marked as
being QAed. When the revision is marked as good, it automatically gets merged
into the `production` branch, which is rolled out to `launchpad.net` daily.		 Branches without db changes (or dependencies on pending db changes) land on the `stable` branch and are rolled out every 30 minutes to a
"QA testing" server for QA. Revisions that have been marked QA-OK are [[https://devpad.canonical.com/~lpqateam/qa_reports/deployment-stable.html|eligible] for deployment.
Deployment takes a specific revision of `stable` and deploys that to a named set of machines. The default set is `nodowntime` which encompasses all services that we can deploy to without user visible downtime.
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{{attachment:merge-workflow.png}} Branches that contain db changes land on the `db-stable` branch, and
are QA'd on staging. The `db-stable` branch automatically merges changes
from `stable` via a push event in Buildbot. DB changes are rolled out
to production and merged back into `stable` once a month.

{{attachment:mergeworkflow.png}}

''(Old image: [[attachment:merge-workflow-draft-2.jpeg]])''
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A revision gets merged from `edge` to `production` only after it has been
marked as good in the QA step. This helps ensure that we don't rollout feature
to `launchpad.net` that haven't been QAed.		 A revision gets deployed only after it has been marked as good in the QA step. This helps ensure that we don't
rollout feature to `launchpad.net` that haven't been QAed.
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XXX: How the QA step works regarding to marking the revision as good/bad is still
undefined.		 In addition to this, a revision only gets deployed if all the previous revisions have been marked as good as
well. This is because cherrypicking can invalidate QA efforts when patches have non-obvious dependencies.

How the QA step works regarding to marking the revision as good/bad is described on [[QAProcessContinuousRollouts]].

=== What if I don't do my QA, or my QA is bad? ===

If someone does not do their QA, or their branch fails QA, then they will
block deployments until that revision is reverted '''and''' the intervening revisions have also been QA'd.
Rollouts from `stable` to the QA server will still continue, so other
developers can still continue their QA as normal.

We assume a two day grace period for QA - if on the third day a branch has
not been QA'd, then anyone on the team may revert the offending revision.
 We must focus on making these reversions as easy and painless as possible.
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== Feature branches == === What if I have to do QA that takes a few days? ===
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Features that will involve multiple branches should have an integration branch
for that feature. Instead of landing branches related to the feature to `edge`,
they land their branches to the integration branch. New revisions in the
integration branch will automatically be merge into the `edge` branch.

The reason for having an integration branch branch is to keep track of all the
revisions that belong to the feature, so that when the feature has been marked
as good in the QA process, the whole feature can be rolled out at once. Parts
of the feature can still be rolled out by QAing specific revisions.

XXX: How to register new feature branches, and how to merge to them, is still
undefined. Maybe a better way would be to use revision properties to tag
revisions as being part of a bigger feature, or use bug links?

=== Resolving conflicts ===

If there's a conflict when automatically merging the feature branch into the `edge` branch, someone has to manually merge the feature branch into `edge` and resolve the conflicts.		 If a feature requires more than one day of QA, then developers have the option
to do the QA on the `staging.launchpad.net` server, to requisition an additional server,
(dogfood), or ask for permission to block the daily QA rollouts for more than
two or three days.
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== Bug fixes == == The Rollout ==
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Bug fixes for features that already exposed on `launchpad.net` can go directly
to the `edge` branch. After the revision has been QAed, it gets merged into the
`production` branch.		  1. Block deployments to all machines
 1. lock down devel landings (to release-critical)
 1. merge the qa-approved changes from db-stable to devel
 1. qastaging will then get the db patches included in it
 1. qa up through the db patch merge and nominate the revision to deploy
 1. unlock devel landings
 1. at the scheduled time do a db deploy of the nominated revision
 1. unlock deployments
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== Large Features That Span Branches ==
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== Continuous rollouts to `launchpad.net` == If you have a feature that will span multiple branches, then it is expected
that the developers will create a [[LEP/FeatureFlags|feature switch]] to optionally enable that
part of the code, or that early branches that have no user-facing changes
will be marked as `qa-untestable`.
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The `production` branch gets rolled out to the web app servers daily, to expose
our users to bug fixes not too long after the fix has been verified to work on
`edge.launchpad.net`.		 == Emergency Fixes/Cherry Picks ==
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We only do this for the web app servers, since we can update them without any
downtime.		 Either (for confidential non-ZOMG fixes):
 1. Block deployments (of the affected servers)
 1. push the current deployed revision to prod-devel
 1. land on prod-devel
 1. deploy from prod stable
 1. merge from prod-stable to devel
 1. wait for qa blessing for everything outstanding up through the fix rev
 1. unblock deployments
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XXX: If we're not ready for this, things could get merged into the `db` branch after being QAed, waiting to get rolled out with the next release.


== What about `staging.launchpad.net` ==

Staging takes the `edge` branch and merges in the `db` branch.		 Or (for zomg fixes):
 1. Block deployments of the affected servers
 1. use a cowboy
 1. Land on devel
 1. wait for qa blessing for everything outstanding up through the fix rev
 1. unblock deployments

This is a description of how a developer branch flows through the different 'official' branches we have, after the developer branch is ready for landing.

Merge Workflow

Branches without db changes (or dependencies on pending db changes) land on the stable branch and are rolled out every 30 minutes to a "QA testing" server for QA. Revisions that have been marked QA-OK are [[https://devpad.canonical.com/~lpqateam/qa_reports/deployment-stable.html|eligible] for deployment. Deployment takes a specific revision of stable and deploys that to a named set of machines. The default set is nodowntime which encompasses all services that we can deploy to without user visible downtime.

Branches that contain db changes land on the db-stable branch, and are QA'd on staging. The db-stable branch automatically merges changes from stable via a push event in Buildbot. DB changes are rolled out to production and merged back into stable once a month.

mergeworkflow.png

(Old image: merge-workflow-draft-2.jpeg)

The QA step

A revision gets deployed only after it has been marked as good in the QA step. This helps ensure that we don't rollout feature to launchpad.net that haven't been QAed.

In addition to this, a revision only gets deployed if all the previous revisions have been marked as good as well. This is because cherrypicking can invalidate QA efforts when patches have non-obvious dependencies.

How the QA step works regarding to marking the revision as good/bad is described on QAProcessContinuousRollouts.

What if I don't do my QA, or my QA is bad?

If someone does not do their QA, or their branch fails QA, then they will block deployments until that revision is reverted and the intervening revisions have also been QA'd. Rollouts from stable to the QA server will still continue, so other developers can still continue their QA as normal.

We assume a two day grace period for QA - if on the third day a branch has not been QA'd, then anyone on the team may revert the offending revision.

  • We must focus on making these reversions as easy and painless as possible.

What if I have to do QA that takes a few days?

If a feature requires more than one day of QA, then developers have the option to do the QA on the staging.launchpad.net server, to requisition an additional server, (dogfood), or ask for permission to block the daily QA rollouts for more than two or three days.

The Rollout

  1. Block deployments to all machines
  2. lock down devel landings (to release-critical)
  3. merge the qa-approved changes from db-stable to devel
  4. qastaging will then get the db patches included in it
  5. qa up through the db patch merge and nominate the revision to deploy
  6. unlock devel landings
  7. at the scheduled time do a db deploy of the nominated revision
  8. unlock deployments

Large Features That Span Branches

If you have a feature that will span multiple branches, then it is expected that the developers will create a feature switch to optionally enable that part of the code, or that early branches that have no user-facing changes will be marked as qa-untestable.

Emergency Fixes/Cherry Picks

Either (for confidential non-ZOMG fixes):

  1. Block deployments (of the affected servers)
  2. push the current deployed revision to prod-devel
  3. land on prod-devel
  4. deploy from prod stable
  5. merge from prod-stable to devel
  6. wait for qa blessing for everything outstanding up through the fix rev
  7. unblock deployments

Or (for zomg fixes):

  1. Block deployments of the affected servers
  2. use a cowboy
  3. Land on devel
  4. wait for qa blessing for everything outstanding up through the fix rev
  5. unblock deployments

MergeWorkflow (last edited 2010-11-08 22:01:23 by lifeless)