[nova][ptg] Ussuri scope containment

Eric Fried openstack at fried.cc
Mon Sep 30 23:09:16 UTC 2019

Nova developers and maintainers-

Every cycle we approve some number of blueprints and then complete a low
percentage [1] of them. Which blueprints go unfinished seems to be
completely random (notably, it appears to have nothing to do with our
declared cycle priorities). This is especially frustrating for consumers
of a feature, who (understandably) interpret blueprint/spec approval as
a signal that they can reasonably expect the feature to land [2].

The cause for non-completion usually seems to fall into one of several
broad categories:

== Inadequate *developer* attention ==
- There's not much to be done about the subset of these where the
contributor actually walks away.

- The real problem is where the developer thinks they're ready for
reviewers to look, but reviewers don't. Even things that seem obvious to
experienced reviewers, like failing CI or "WIP" in the commit title,
will cause patches to be completely ignored -- but unseasoned
contributors don't necessarily understand even that, let alone more
subtle issues. Consequently, patches will languish, with each side
expecting the other to take the next action. This is a problem of
culture: contributors don't understand nova reviewer procedures and

== Inadequate *reviewer* attention ==
- Upstream maintainer time is limited.

- We always seem to have low review activity until the last two or three
weeks before feature freeze, when there's a frantic uptick and lots gets

- But there's a cultural rift here as well. Getting maintainers to care
about a blueprint is hard if they don't already have a stake in it. The
"squeaky wheel" concept is not well understood by unseasoned
contributors. The best way to get reviews is to lurk in IRC and beg.
Aside from not being intuitive, this can also be difficult logistically
(time zone pain, knowing which nicks to ping and how) as well as
interpersonally (how much begging is enough? too much? when is it

== Multi-release efforts that we knew were going to be multi-release ==
These may often drag on far longer than they perhaps should, but I'm not
going to try to address that here.


There's nothing new or surprising about the above. We've tried to
address these issues in various ways in the past, with varying degrees
of effectiveness.

I'd like to try a couple more.

(A) Constrain scope, drastically. We marked 25 blueprints complete in
Train [3]. Since there has been no change to the core team, let's limit
Ussuri to 25 blueprints [4]. If this turns out to be too few, what's the
worst thing that happens? We finish everything, early, and wish we had
done more. If that happens, drinks are on me, and we can bump the number
for V.

(B) Require a core to commit to "caring about" a spec before we approve
it. The point of this "core liaison" is to act as a mentor to mitigate
the cultural issues noted above [5], and to be a first point of contact
for reviews. I've proposed this to the spec template here [6].



[1] Like in the neighborhood of 60%. This is anecdotal; I'm not aware of
a good way to go back and mine actual data.
[2] Stuff happens, sure, and nobody expects 100%, but 60%? Come on, we
have to be able to do better than that.
[3] https://blueprints.launchpad.net/nova/train
[4] Recognizing of course that not all blueprints are created equal,
this is more an attempt at a reasonable heuristic than an actual
expectation of total size/LOC/person-hours/etc. The theory being that
constraining to an actual number, whatever the number may be, is better
than not constraining at all.
[5] If you're a core, you can be your own liaison, because presumably
you don't need further cultural indoctrination or help begging for reviews.
[6] https://review.opendev.org/685857

More information about the openstack-discuss mailing list