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From Sean Busbey <bus...@cloudera.com>
Subject Re: [DISCUSSION] Switching from RTC to CTR
Date Sat, 15 Aug 2015 04:00:45 GMT
My apologies if this thread has run its course and I'm showing up late to
rehash things.

Here's a short list of the reasons I like RTC:

1) Number One With A Bullet: It puts committers and
non-committer-contributors on closer to equal footing. If I'm participating
in the project and I haven't been blessed with a commit bit, what am I
supposed to do after my week of having my patch sit around?

2) Community interaction. As Stack mentioned, having the communal norm of
reviews means that folks are more likely to see more of the code.

3) Everyone has a bad day. I totally identify with committership being a
sign of "I trust you" to project participants. But everyone has one of
those days where you're in a rush either because of work or life. Having
even a cursory additional set of eyes on things markedly increases the
quality of the overall code base over a long enough time line (at least in
my experience contributing to open source projects). So for me, the trust
is largely "to follow the rules" and "to provide feedback in reviews".

If we end up with some part of the code that isn't getting reviews, I'd
rather the PMC fix that problem instead of backslide on the three points
above.

That we don't have this problem right now is wonderful. I have been in / am
currently in some projects where the community is very near end-of-life by
the ASF's definition of 3 folks to approve a release. My observation of
those communities has the CTR ones much more a loose collection of people
scratching their own itch. When an ASF project gets to that point, what the
advantage over just going to the attic and keeping independent forks for
those few remaining folks?

I kind of view this like the ASF policy on only distributing PMC approved
releases. The advice from the foundation for folks who don't like the
limitation of waiting for a release is "make more releases." Similarly, I
think the problem of reviewer bandwidth is solved with "make more
committers."

I don't want to hijack this thread, but maybe we could have another one
about expectations for committership and ways the PMC could help get more
folks on the path?


On Sun, Aug 2, 2015 at 1:59 PM, Andrew Purtell <andrew.purtell@gmail.com>
wrote:

> Agreed, committers should be spending more time reviewing others' work. We
> can ask. It may happen. It may work for a short while. It may not. Shrug.
> People will do what they want.
>
> I'm looking to make one substantial change that will allow committers to
> make progress even if there's nobody else around or interested for one
> week. It happens sometimes. I've already talked about my concerns on
> assuming a certain level of available volunteer bandwidth. Let me just say
> that things are great now, it's fantastic.
>
> We are pretty much on the honor system already. I don't buy the argument
> we can't trust that CTR or CTR after one week can work because committers,
> even if asked to customarily get a review before commit, may decide to
> check in unreviewed untested destabilizing changes. At least, In that case
> I'd argue we have a different problem. If you go back to my original mail,
> I do say we shouldn't undertake any change if we as PMC are unwilling to
> revoke the commit bit from committers who sadly demonstrate themselves
> unworthy of trust through checkins of toxic waste without review. Merit
> _can_ be un-earned. Commits can be reverted. Just because something is
> checked in does not mean it will go out in a release. We could put a
> nightly suite of regression tests in place. Both proposals I have made,
> especially the latter, are not a binary release of any attempt at quality
> control. We would have all of the consensus expectations of good committer
> behavior still in place.
>
> Let's assume someone checks in something without getting a review today.
> What would happen? Someone else would revert it and we'd have a discussion.
> If we were operating under CTR-after-one-week (or plain CTR) but with
> documented expectations that someone get a review first, what changes, in
> terms of quality control and project discipline? Maybe the difference is we
> could more easily justify revoking commit privileges? Maybe. I think every
> discussion like that would be strictly case by case though, a conversation
> between that person and the PMC, justification for revoking committer
> status wouldn't be rule based.
>
> What definitely would change is my well tested good faith change waiting
> for review after one week could go in no matter who's on vacation or
> whatever. Not saying this is a problem for me today. Like I said, things
> are great around here today. Awesome.
>
>
> > On Aug 2, 2015, at 10:52 AM, Stack <stack@duboce.net> wrote:
> >
> > On Fri, Jul 31, 2015 at 3:15 AM, Andrew Purtell <
> andrew.purtell@gmail.com>
> > wrote:
> >
> >> I appreciate very much the earlier feedback about switching from RTC to
> >> CTR. It helped me think about the essential thing I was after.
> >>
> >> I'm thinking of making a formal proposal to adopt this, with a VOTE:
> >>
> >>> After posting a patch to JIRA, after one week if there is no review or
> >> veto, a committer can commit their own work.
> >>
> >> (On a bit of a lag...)
> >
> > What is the problem we are trying to solve? Blocked committers unable to
> > get a review?
> >
> > Any commit can destabilize. Commits without peer review will destabilize
> > more than those that have been reviewed. As a community, I'd think that
> > anything we can do to act against entropy in the system would be primary
> > above all other considerations especially given our project a mature
> > datastore.
> >
> > In my own case, it seems to take me tens of patch postings to arrive at
> > something a fellow reviewer thinks worthy of commit when working with a
> > peer on an issue of substance. Often the final patch is radically
> different
> > from first posting. If auto-commit, the first version would just go in.
> > Unless review, I'd be 'done'. If review, each iteration would be in the
> > code base? Churn would go up. Commits would be more and smaller. Our
> > project would be made of less coherent 'change sets'.
> >
> > I'd be with LarsH suggestion that committers should be allowed go ahead
> > with one-liners or more substantial, non-controversial changes in site or
> > doc but beyond this, I'd be against auto-commit.
> >
> >>
> >>
> >> Also, looking at https://hbase.apache.org/book.html#_decisions, I don't
> >> think the "patch +1 policy" should remain because the trial OWNERS
> concept
> >> hasn't worked out, IMHO. The OWNERS concept requires a set of constantly
> >> present and engaged owners, a resource demand that's hard to square with
> >> the volunteer nature of our community. The amount of time any committer
> or
> >> PMC member has on this project is highly variable day to day and week to
> >> week.  I'm also thinking of calling a VOTE to significantly revise or
> >> strike this section.
> > Yeah. OWNERS project failed. Its ghost is in effect in that we each go to
> > the domain expert when its clear (e.g. Matteo or Stephen on pv2).
> >
> >
> >> Both of these things have a common root: Volunteer time is a very
> precious
> >> commodity. Our community's supply of volunteer time fluctuates. I would
> >> like to see committers be able to make progress with their own work
> even in
> >> periods when volunteer time is in very short supply, or when they are
> >> working on niche concerns that simply do not draw sufficient interest
> from
> >> other committers. (This is different from work that people think isn't
> >> appropriate - in that case ignoring it so it will go away would no
> longer
> >> be an option, a veto would be required if you want to stop something.)
> > Committers should be spending more time reviewing their peers work (and
> > just as importantly, the work of contributors)?
> > St.Ack
> >
> >
> >
> >> On Wed, Jul 29, 2015 at 3:56 PM, Andrew Purtell <
> andrew.purtell@gmail.com>
> >> wrote:
> >>
> >>> Had this thought after getting back on the road. As an alternative to
> any
> >>> sweeping change we could do one incremental but very significant thing
> >> that
> >>> acknowledges our status as trusted and busy peers: After posting a
> patch
> >> to
> >>> JIRA, after one week if there is no review or veto, a committer can
> >> commit
> >>> their own work.
> >>>
> >>>
> >>>>> On Jul 29, 2015, at 2:20 PM, Mikhail Antonov <olorinbant@gmail.com>
> >>>> wrote:
> >>>>
> >>>> Just curious, I assume if this change is made, would it only apply to
> >>>> master branch?
> >>>>
> >>>> -Mikhail
> >>>>
> >>>> On Wed, Jul 29, 2015 at 2:09 PM, Andrew Purtell
> >>>> <andrew.purtell@gmail.com> wrote:
> >>>>> @dev is now CCed
> >>>>>
> >>>>> I didn't want to over structure the discussion with too much detail
> up
> >>> front. I do think CTR without supporting process or boundaries can be
> >> more
> >>> problematic than helpful. That could take the form of customarily
> waiting
> >>> for reviews before commit even under a CTR regime. I think this
> >> discussion
> >>> has been great so far. I would also add that CTR moves 'R' from a
> gating
> >>> requirement per commit (which can be hard to overcome for niche areas
> or
> >>> when volunteer resources are less available) more to RMs. will be back
> >>> later with more.
> >>>>>
> >>>>>
> >>>>>> On Jul 29, 2015, at 1:36 PM, Sean Busbey <sean.busbey@gmail.com>
> >>> wrote:
> >>>>>>
> >>>>>> I'd also favor having this discussion on dev@.
> >>>>>>
> >>>>>>> On Wed, Jul 29, 2015 at 2:29 PM, Gary Helmling <
> ghelmling@gmail.com
> >>>
> >>> wrote:
> >>>>>>>
> >>>>>>> This is already a really interesting and meaningful discussion,
and
> >> is
> >>>>>>> obviously important to the community.
> >>>>>>>
> >>>>>>> Is there any reason not to move this straight to the dev@
list?
> >>>>>>>
> >>>>>>>> On Wed, Jul 29, 2015 at 11:40 AM Todd Lipcon <todd@cloudera.com>
> >>> wrote:
> >>>>>>>>
> >>>>>>>> I'm not very active in HBase these days, so I won't
cast a
> non-zero
> >>> vote,
> >>>>>>>> but I'm -0 on this idea, for basically two reasons:
> >>>>>>>>
> >>>>>>>> 1) In my experience at a past job which used CTR, the
reality was
> >>> that it
> >>>>>>>> was more like "Commit and maybe review" rather than
"Commit then
> >>> review".
> >>>>>>>> It's always more fun (and often easier) to write new
code than to
> >>> review
> >>>>>>>> other people's code, so if there isn't a requirement
that all code
> >>> gets
> >>>>>>>> reviewed before commit, it's easy for the ratio of code
written to
> >>> code
> >>>>>>>> reviewed to tend towards values significantly greater
than 1:1
> over
> >>> time.
> >>>>>>>> At my past job, this meant that a lot of code made it
into
> >>> production (it
> >>>>>>>> was a website) that hadn't ever been reviewed, and in
many cases
> we
> >>> found
> >>>>>>>> bugs (or other issues) that would have definitely been
caught by a
> >>> good
> >>>>>>>> code reviewer.
> >>>>>>>>
> >>>>>>>> 2) CTR has both the advantage and disadvantage of allowing
areas
> of
> >>> code
> >>>>>>> to
> >>>>>>>> be evolved quickly by a single person. That could be
seen as a
> >> plus,
> >>> in
> >>>>>>>> that there are some areas which tend to get ignored
because we
> >> don't
> >>>>>>> have a
> >>>>>>>> critical mass of people reviewing patches in the area
-- patches
> >>> languish
> >>>>>>>> in these areas currently. However, that could also be
seen as a
> >> good
> >>>>>>> thing
> >>>>>>>> from a "community over code" perspective -- it's better
to not
> have
> >>> any
> >>>>>>>> areas of code with bus-factor 1. Feeling the pain of
not getting
> >>> reviews
> >>>>>>> in
> >>>>>>>> these areas with only a single active committer encourages
us to
> >> find
> >>>>>>>> solutions - either by deprecating "niche" features (as
we once did
> >>> with
> >>>>>>>> various 'contrib' projects) or by recruiting new committers
who
> >> have
> >>>>>>>> interest in maintaining that code area. Lifting review
> restrictions
> >>> would
> >>>>>>>> allow us to sweep bus-factor issues under the rug.
> >>>>>>>>
> >>>>>>>> That said, I think CTR can be a valuable tool for "move
fast on
> new
> >>>>>>>> experimentation" type projects -- I've participated
in several
> >>> feature
> >>>>>>>> branches in HDFS where we operated on CTR on the branch.
The
> >>> assumption
> >>>>>>> was
> >>>>>>>> that, prior to merging the branch into trunk, all of
the patches
> >> (or
> >>> a
> >>>>>>>> consolidated mega-patch) would be thoroughly reviewed
by several
> >>> other
> >>>>>>>> committers. I found this to work very well during early
> >> development,
> >>>>>>> since
> >>>>>>>> I could hack on things and even commit pieces of code
that had
> >> known
> >>>>>>>> issues/TODOs. For trickier patches on the CTR branch,
I still
> >> tended
> >>> to
> >>>>>>>> ping experienced contributors for their opinions and
feedback
> >> before
> >>>>>>>> committing.
> >>>>>>>>
> >>>>>>>> Perhaps such a hybrid policy would work well in the
context of
> >> HBase
> >>>>>>>> feature development as well?
> >>>>>>>>
> >>>>>>>> -Todd
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On Wed, Jul 29, 2015 at 11:27 AM, Andrew Purtell <
> >>> apurtell@apache.org>
> >>>>>>>> wrote:
> >>>>>>>>
> >>>>>>>>> Just thought of branch merge votes. Sorry for that
omission. I
> >>> think it
> >>>>>>>>> makes sense to keep those, but let's discuss that
too in this
> >>> context.
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> On Wed, Jul 29, 2015 at 11:26 AM, Andrew Purtell
<
> >>> apurtell@apache.org>
> >>>>>>>>> wrote:
> >>>>>>>>>
> >>>>>>>>>> As Greg Stein said on a thread over at general@incubator
> >>>>>>>> ("[DISCUSSION]
> >>>>>>>>>> Graduate Ignite from the Apache Incubator"):
> >>>>>>>>>>
> >>>>>>>>>> I always translate RTC as "we don't trust you,
so somebody else
> >>> must
> >>>>>>>>>> approve anything you do." To me, that is a lousy
basis for
> >>> creating a
> >>>>>>>>>> community. Trust and peer respect should be
the basis, which
> >>> implies
> >>>>>>>> CTR.
> >>>>>>>>>>
> >>>>>>>>>> I happen to agree with this sentiment and would
like to propose
> >>>>>>>> switching
> >>>>>>>>>> our consensus on commit procedure from RTC to
CTR. Concurrently,
> >> I
> >>>>>>>> would
> >>>>>>>>>> like to propose this consensus also include
the following:
> >>>>>>>>>> - Checkins should pass precommit or the committer
should explain
> >> on
> >>>>>>> the
> >>>>>>>>>> JIRA why precommit failures are in their best
judgement not
> >> related
> >>>>>>>>>> - The PMC should be willing to, ultimately,
revoke committership
> >>>>>>> should
> >>>>>>>>>> trust in any individual committer be discovered
to be misplaced.
> >> I
> >>>>>>>> would
> >>>>>>>>>> expect such a last resort to be exceedingly
rare and likely
> never
> >>> to
> >>>>>>>>> happen
> >>>>>>>>>> because of course long before that we would
be setting correct
> >>> public
> >>>>>>>>>> examples in the first place and respectfully
counseling well
> >>>>>>>> intentioned
> >>>>>>>>>> committers who might stray.
> >>>>>>>>>>
> >>>>>>>>>> Depending on how the conversation proceeds here
I would like to
> >>>>>>> include
> >>>>>>>>>> dev@ in this conversation at the earliest opportunity
as well.
> >>>>>>>>>>
> >>>>>>>>>> Thoughts?
> >>>>>>>>>>
> >>>>>>>>>> --
> >>>>>>>>>> Best regards,
> >>>>>>>>>>
> >>>>>>>>>> - Andy
> >>>>>>>>>>
> >>>>>>>>>> Problems worthy of attack prove their worth
by hitting back. -
> >> Piet
> >>>>>>>> Hein
> >>>>>>>>>> (via Tom White)
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> Best regards,
> >>>>>>>>>
> >>>>>>>>> - Andy
> >>>>>>>>>
> >>>>>>>>> Problems worthy of attack prove their worth by hitting
back. -
> >> Piet
> >>>>>>> Hein
> >>>>>>>>> (via Tom White)
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> --
> >>>>>>>> Todd Lipcon
> >>>>>>>> Software Engineer, Cloudera
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> Sean
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> Thanks,
> >>>> Michael Antonov
> >>
>



-- 
Sean

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