[Gluster-devel] Gerrit review, submit type and Jenkins testing

Fri Jan 8 06:33:08 UTC 2016

Top posting, this is a very old thread.

Keeping in view the recent NetBSD problems and the number of bugs creeping
in, I suggest we do these things right now:

a. Change the gerrit merge type to fast forward only.
As explained below in the thread, with our current setup even if both
PatchA and PatchB pass regression separately when both are merged it is
possible that a functional bug creeps in.
This is the only solution to prevent that from happening.
I will work with Kaushal to get this done.

b. In Jenkins, remove gerrit trigger and make it a manual operation

Too many developers use the upstream infra as a test cluster and it is
*not*.
It is a verification mechanism for maintainers to ensure that the patch
does not cause regression.
It is required that all developers run full regression on their machines
before asking for reviews.
Reviewers should review the patch only when the developer has given a +1
verified on the patch.
Again, I will work with Kaushal to get this done.

P.S: Stop using the "universal" jenkins account to trigger jenkins build if
you are not a maintainer.
If you are a maintainer and don't have your own jenkins account then get
one soon!

Thanks,
Raghavendra Talur

On Tue, Nov 10, 2015 at 11:33 AM, Atin Mukherjee <atin.mukherjee83 at gmail.com
> wrote:

> -Atin
> Sent from one plus one
>
> On Nov 10, 2015 11:24 AM, "Kaushal M" <kshlmster at gmail.com> wrote:
> >
> > On Tue, Nov 10, 2015 at 9:24 AM, Raghavendra Gowdappa
> > <rgowdapp at redhat.com> wrote:
> > >
> > >
> > > ----- Original Message -----
> > >> From: "Raghavendra Talur" <rtalur at redhat.com>
> > >> To: "Gluster Devel" <gluster-devel at gluster.org>
> > >> Sent: Tuesday, November 10, 2015 3:10:34 AM
> > >> Subject: [Gluster-devel] Gerrit review, submit type and Jenkins
> testing
> > >>
> > >> Hi,
> > >>
> > >> While trying to understand how our gerrit+jenkins setup works, I
> realized of
> > >> a possibility of allowing bugs to get in.
> > >>
> > >> Currently, our gerrit is setup to have cherry-pick as the submit
> type. Now
> > >> consider a case where:
> > >>
> > >> Dev1 sends a commit B with parent commit A(A is already merged).
> > >> Dev2 sends a commit C with parent commit A(A is already merged).
> > >>
> > >> Both the patches get +2 from Jenkins.
> > >>
> > >> Maintainer merges commit B from Dev1.
> > >> Another maintainer merges commit C from Dev2.
> > >>
> > >> If the two commits B and C changed code which had no merge conflicts
> but were
> > >> conflicting in logic,
> > >> then we have a master which has bugs.
> > >>
> > >> If Dev3 now sends a commit D with re-based master as parent, we have
> the
> > >> following cases:
> > >>
> > >> 1. If bug introduced above is not racy, we have tests always failing
> for Dev3
> > >> on commit D. Tests that fail would be from components that commit B
> and C
> > >> changed. Dev3 has no idea on how to fix them and has to enlist help
> from
> > >> Dev1 and Dev2.
> > >>
> > >> 2. If bug introduced above is racy, then there is a probability that
> Dev3
> > >> escapes from this trouble and someone else will bear it later. Even
> if the
> > >> racy code is hit and test fails, Dev3 will probably re-trigger the
> tests
> > >> given that they failed for a component which is not related to
> his/her code
> > >> and the bug stays in code longer.
> > >>
> > >> The most obvious but not practical solution to the above problem is
> to change
> > >> the submit type in gerrit to "fast-forward only". It would then
> ensure that
> > >> once commit B is merged, Dev2 has to re-base and re-run the tests on
> commit
> > >> C with commit B as parent, before it could be merged. It is not
> practical
> > >> because it will cause all patches in review to get re-based and
> re-triggered
> > >> whenever a patch is merged.
> > >>
> > >> A little modification to the above solution would be to
> > >>
> > >>
> > >>     * change submit type to fast-forward only
> > >>     * don't run any jenkins job on patches till they get +2 from
> reviewers
> > >>     * once a +2 is given, run jenkins job on patch and automatically
> submit
> > >>     it if test passes.
> > >>     * automatically rebase all patches on review with new master and
> mark
> > >>     conflict if merge conflict arises.
> > >
> > > Seems like a good suggestion. How about a slight variation to the
> above process? Can we run one initial set of regression immediately after
> submission, but before any reviews? That way reviewers can prioritize those
> patches that have passed regression over the ones that have failed? Flip
> side is that minimum two sets of regressions are needed to merge any patch.
> I am making this suggestion with the assumption that dev/reviewer time is
> more precious than machine time. Of course, this will have issues with
> patches that need to get in urgently (user/customer hot fix etc) where time
> is a constraint. But that can be worked around on a case-by-case basis.
> >
> > We would still be running smoke, which would catch any very obvious
> > mistakes, isn't this enough?
> >
> > Regarding the initial regression run, would it include the complete
> > regression suite or just a subset. If it is the complete set, then it
> > would be no different from what we are doing now. If it is a subset,
> > then we will need to come up with a subset of the regression suite
> > that catches most of obvious mistakes. We've had discussions several
> > times (don't remember if it was on the mailing lists, but I have had
> > conversations) about doing this. Every time we ended up on the
> > question of how we choose the subset, which is where we stopped.
> How about running tests/basic/*.t? I know coverage wise this isn't good
> enough, but still better than running everything or nothing.
> >
> > >
> > >>
> > >> As a side effect of this, Dev would now be forced to run a complete
> > >> regression on dev machine before sending a patch for review.
> > >>
> > >> Any thoughts on the above solutions or other suggestions?
> > >>
> > >> Thanks,
> > >> Raghavendra Talur
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> _______________________________________________
> > >> Gluster-devel mailing list
> > >> Gluster-devel at gluster.org
> > >> http://www.gluster.org/mailman/listinfo/gluster-devel
> > > _______________________________________________
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> > > Gluster-devel at gluster.org
> > > http://www.gluster.org/mailman/listinfo/gluster-devel
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> > Gluster-devel at gluster.org
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>
>
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