Re: [PATCH] gitlab: remove unreliable avocado CI jobs

[Stefan Hajnoczi <stefanha@gmail.com>]

On Tue, 12 Sept 2023 at 14:36, Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Stefan Hajnoczi <stefanha@gmail.com> writes:
>
> > On Tue, Sep 12, 2023, 12:14 Daniel P. Berrangé <berrange@redhat.com> wrote:
> >
> >  On Tue, Sep 12, 2023 at 05:01:26PM +0100, Alex Bennée wrote:
> >  >
> >  > Daniel P. Berrangé <berrange@redhat.com> writes:
> >  >
> >  > > On Tue, Sep 12, 2023 at 11:06:11AM -0400, Stefan Hajnoczi wrote:
> >  > >> The avocado-system-alpine, avocado-system-fedora, and
> >  > >> avocado-system-ubuntu jobs are unreliable. I identified them while
> >  > >> looking over CI failures from the past week:
> >  > >> https://gitlab.com/qemu-project/qemu/-/jobs/5058610614
> >  > >> https://gitlab.com/qemu-project/qemu/-/jobs/5058610654
> >  > >> https://gitlab.com/qemu-project/qemu/-/jobs/5030428571
> >  > >>
> >  > >> Thomas Huth suggest on IRC today that there may be a legitimate failure
> >  > >> in there:
> >  > >>
> >  > >>   th_huth: f4bug, yes, seems like it does not start at all correctly on
> >  > >>   alpine anymore ... and it's broken since ~ 2 weeks already, so if nobody
> >  > >>   noticed this by now, this is worrying
> >  > >>
> >  > >> It crept in because the jobs were already unreliable.
> >  > >>
> >  > >> I don't know how to interpret the job output, so all I can do is to
> >  > >> propose removing these jobs. A useful CI job has two outcomes: pass or
> >  > >> fail. Timeouts and other in-between states are not useful because they
> >  > >> require constant triaging by someone who understands the details of the
> >  > >> tests and they can occur when run against pull requests that have
> >  > >> nothing to do with the area covered by the test.
> >  > >>
> >  > >> Hopefully test owners will be able to identify the root causes and solve
> >  > >> them so that these jobs can stay. In their current state the jobs are
> >  > >> not useful since I cannot cannot tell whether job failures are real or
> >  > >> just intermittent when merging qemu.git pull requests.
> >  > >>
> >  > >> If you are a test owner, please take a look.
> >  > >>
> >  > >> It is likely that other avocado-system-* CI jobs have similar failures
> >  > >> from time to time, but I'll leave them as long as they are passing.
> >  > >>
> >  > >> Buglink: https://gitlab.com/qemu-project/qemu/-/issues/1884
> >  > >> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> >  > >> ---
> >  > >>  .gitlab-ci.d/buildtest.yml | 27 ---------------------------
> >  > >>  1 file changed, 27 deletions(-)
> >  > >>
> >  > >> diff --git a/.gitlab-ci.d/buildtest.yml b/.gitlab-ci.d/buildtest.yml
> >  > >> index aee9101507..83ce448c4d 100644
> >  > >> --- a/.gitlab-ci.d/buildtest.yml
> >  > >> +++ b/.gitlab-ci.d/buildtest.yml
> >  > >> @@ -22,15 +22,6 @@ check-system-alpine:
> >  > >>      IMAGE: alpine
> >  > >>      MAKE_CHECK_ARGS: check-unit check-qtest
> >  > >>
> >  > >> -avocado-system-alpine:
> >  > >> -  extends: .avocado_test_job_template
> >  > >> -  needs:
> >  > >> -    - job: build-system-alpine
> >  > >> -      artifacts: true
> >  > >> -  variables:
> >  > >> -    IMAGE: alpine
> >  > >> -    MAKE_CHECK_ARGS: check-avocado
> >  > >
> >  > > Instead of entirely deleting, I'd suggest adding
> >  > >
> >  > >    # Disabled due to frequent random failures
> >  > >    # https://gitlab.com/qemu-project/qemu/-/issues/1884
> >  > >    when: manual
> >  > >
> >  > > See example: https://docs.gitlab.com/ee/ci/yaml/#when
> >  > >
> >  > > This disables the job from running unless someone explicitly
> >  > > tells it to run
> >  >
> >  > What I don't understand is why we didn't gate the release back when they
> >  > first tripped. We should have noticed between:
> >  >
> >  >   https://gitlab.com/qemu-project/qemu/-/pipelines/956543770
> >  >
> >  > and
> >  >
> >  >   https://gitlab.com/qemu-project/qemu/-/pipelines/957154381
> >  >
> >  > that the system tests where regressing. Yet we merged the changes
> >  > anyway.
> >
> >  I think that green series is misleading, based on Richard's
> >  mail on list wrt the TCG pull series:
> >
> >    https://lists.gnu.org/archive/html/qemu-devel/2023-08/msg04014.html
> >
> >    "It's some sort of timing issue, which sometimes goes away
> >     when re-run. I was re-running tests *a lot* in order to
> >     get them to go green while running the 8.1 release. "
>
> But I think in that actual case a change exposed a race condition which
> has only recently been fixed - however we've had additional regresssions
> since.
>
> Rather than kill the system tests we can disable the flaky individual
> tests in avocado.

That would be nice, please send an alternative patch.

I can't do that myself because there are a bunch of test cases with
suspicious output and I don't know which ones are legitimate failures,
intermittent problems, or expected failures.

Stefan

>
> >
> >  Essentially I'd put this down to the tests being soo non-deterministic
> >  that we've given up trusting them.
> >
> > Yes.
> >
> > Stefan
> >
> >  With regards,
> >  Daniel
> >  --
> >  |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> >  |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> >  |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|
>
>
> --
> Alex Bennée
> Virtualisation Tech Lead @ Linaro