TripleO Review Standards

No launchpad blueprint because this isn’t a spec to be implemented in code.

Like many OpenStack projects, TripleO generally has more changes incoming to the projects than it has core reviewers to review and approve those changes. Because of this, optimizing reviewer bandwidth is important. This spec will propose some changes to our review process discussed at the Paris OpenStack Summit and intended to make the best possible use of core reviewer time.

There are essentially two major areas that a reviewer looks at when reviewing a given change: design and implementation. The design part of the review covers things like whether the change fits with the overall direction of the project and whether new code is organized in a reasonable fashion. The implementation part of a review will get into smaller details, such as whether language functionality is being used properly and whether the general sections of the code identified in the design part of the review do what is intended.

Generally design is considered first, and then the reviewer will drill down to the implementation details of the chosen design.

Problem Description

Many times an overall design for a given change will be agreed upon early in the change’s lifecycle. The implementation for the design may then be tweaked multiple times (due to rebases, or specific issues pointed out by reviewers) without any changes to the overall design. Many times these implementation details are small changes that shouldn’t require much review effort, but because of our current standard of 2 +2’s on the current patch set before a change can be approved, reviewers often must unnecessarily revisit a change even when it is clear that everyone involved in the review is in favor of it.

Proposed Change


When appropriate, allow a core reviewer to approve a change even if the latest patch set does not have 2 +2’s. Specifically, this should be used under the following circumstances:

  • A change that has had multiple +2’s on past patch sets, indicating an agreement from the other reviewers that the overall design of the change is good.

  • Any further alterations to the change since the patch set(s) with +2’s should be implementation details only - trivial rebases, minor syntax changes, or comment/documentation changes. Any more significant changes invalidate this option.

As always, core reviewers should use their judgment. When in doubt, waiting for 2 +2’s to approve a change is always acceptable, but this new policy is intended to make it socially acceptable to single approve a change under the circumstances described above.

When approving a change in this manner, it is preferable to leave a comment explaining why the change is being approved without 2 +2’s.


Allowing a single +2 on “trivial” changes was also discussed, but there were concerns from a number of people present that such a policy might cause more trouble than it was worth, particularly since “trivial” changes by nature do not require much review and therefore don’t take up much reviewer time.

Security Impact

Should be minimal to none. If a change between patch sets is significant enough to have a security impact then this policy does not apply.

Other End User Impact


Performance Impact


Other Deployer Impact


Developer Impact

Core reviewers will spend less time revisiting patches they have already voted in favor of, and contributors should find it easier to get their patches merged because they won’t have to wait as long after rebases and minor changes.



Primary assignee:


Other contributors:

All cores should review and implement this spec in their reviewing

Work Items

Publish the agreed-upon guidelines somewhere more permanent than a spec.





Documentation Impact

A new document will need to be created for core reviewers to reference.