[openstack-dev] [Cinder] [stable] [all] Changing stable policy for drivers

Luigi Toscano ltoscano at redhat.com
Wed Aug 10 16:33:54 UTC 2016

On Wednesday, 10 August 2016 12:00:41 CEST Ben Swartzlander wrote:
> On 08/10/2016 11:33 AM, Luigi Toscano wrote:
> > On Wednesday, 10 August 2016 17:00:36 CEST Ihar Hrachyshka wrote:
> >> Luigi Toscano <ltoscano at redhat.com> wrote:
> >>> On Wednesday, 10 August 2016 10:42:41 CEST Ben Swartzlander wrote:
> >>>> On 08/10/2016 04:33 AM, Duncan Thomas wrote:
> >>>>> So I tried to get into helping with the cinder stable tree for a
> >>>>> while,
> >>>>> and while I wasn't very successful (lack of time and an inability to
> >>>>> convince my employer it should be a priority), one thing I did notice
> >>>>> it
> >>>>> that much of the breakage seemed to come from outside cinder - many of
> >>>>> the libraries we depend on make backwards incompatible changes by
> >>>>> accident, for example. Would it be possible to have a
> >>>>> long-term-support
> >>>>> branch where we pinned the max version of everything for the gate,
> >>>>> pips
> >>>>> and devtstack? I'd have thought (and I'm very willing to be corrected)
> >>>>> that would make the stable gate, well, stable, such that it required
> >>>>> far
> >>>>> less work to keep it able to run a basic devstack test plus unit
> >>>>> tests.
> >>>>> 
> >>>>> Does that sound at all sane?
> >>>> 
> >>>> A big source of problems IMO is that tempest doesn't have stable
> >>>> branches. We use the master branch of tempest to test stable branches
> >>>> of
> >>>> other projects, and tempest regularly adds new features. This
> >>>> guarantees
> >>>> instability if you rely on tempest anywhere in your gate (and cinder
> >>>> does).
> >>> 
> >>> Orthogonal to the discussion, but: this is not due to the lack of stable
> >>> branch, but that part of the Tempest API are not stable yet. This is
> >>> being
> >>> addressed right now (in scope for Newton).
> >>> Once the Tempest stable API are used, no breakages should happen.
> >> 
> >> Well, it’s only partially true. But what happens when you add a new test
> >> to
> >> tempest/master? It gets executed on all branches, and maybe some of them
> >> are failing it. We can argue that it’s probably a bug revealed, but it
> >> nevertheless requires attention from stable maintainers to solve.
> > 
> > The new test should work on all support branches. As tester I find a lot
> > of
> > advantages of maintaining a unified set of tests than fighting with
> > backports of tests.
> I'm sure it makes YOUR life easier to not have to deal with backports.
> The rest of us who do maintain stable branches though don't appreciate
> it when tempest adds a new feature or a new dependency which breaks the
> stable gate jobs. This happens a few times each release, and tends to
> get fixed within a day or two, which is barely tolerable.

Again, if a new test uncover the bug, why blame the test and not the bug?

If you don't want to fix bugs in stable branches, why keep them?

I don't understand...

> The fact that it happens at all though says that we're "doing it wrong"
> w.r.t. testing of stable branches, and completely explains why we find
> it so challenging to support stuff more than 12 months old. If
> everything we used had stable branches and proper dependency management,
> then it would easy to keep gate job running for years.

Again, if a test uncover a bugs, let fix the bug.

> > There are mechanisms to skip tests based on the cloud capabilities.
> > So this should not be an issue, and if a bug is found that should
> > definitely be viewed as a good thing.
> It's not new tests that cause the problem, because those would be easy
> to skip. It's changes to tempest core which force changes elsewhere.

As I mentioned before, that's something temporary, due to the change of scope 
of Tempest (the core six, the plugin systems) and the stabilization of that's 
ongoing for Newton, so *right now*.
We will forget quickly about all of this once its fixed (more or less like the 
old complains about Neutron - rememeber?). 
Patches always welcome to speed up the Tempest API stabilization.


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