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

["Alex Bennée" <alex.bennee@linaro.org>]

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. 

>
>  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
>  -- 
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-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro