Chia-Ping, I think something like that can work. I was also thinking about
extracting the test names during trunk builds using Gradle and storing that
somewhere. I think it's fair to say we can derive this data from Git and
Develocity. We can probably figure out the implementation details later on
:)
I've updated the KIP to describe the two-tiered approach as well as
including a diagram.
-David
On Thu, Sep 19, 2024 at 12:40 PM Chia-Ping Tsai <chia7...@gmail.com> wrote:
> > However, this doesn't help with the newly added tests that introduce
> flakiness. For this, we need some way
> to detect when a new test has been added. Still thinking through this...
>
> Maybe we can use git + gradle develocity to address it.
>
> 1) list the files changed recently (for example: git diff --name-only "@{7
> days ago}")
> 2) use the test-related filename to query Gradle Develocity with "7 days
> ago"
> 3) the test cases having fewer builds are viewed as "new tests"
>
> WDYT?
>
> David Arthur <mum...@gmail.com> 於 2024年9月19日 週四 下午11:56寫道：
>
> > TengYao,
> >
> > > These two mechanisms are independent. We could manually remove a tag
> from
> > a
> > test, but at the same time, it might still be quarantined.
> > I know the above situation might sound weird, but I just want to
> understand
> > how it would work.
> >
> > If we remove a tag from a test, we are signaling that we *think* it is
> now
> > stable. However, until we have data
> > to prove that, we can run the test in the quarantine. This helps with the
> > situation where there are multiple
> > sources of flakiness and we are making iterative progress on improving
> it.
> >
> > The alternative is to keep the fix in a PR until the developer gets
> enough
> > signal from the PR builds to be
> > convinced that the flakiness is gone. I mention in the KIP that this
> > approach has issues.
> >
> >
> > Chia-Ping,
> >
> > > If so, could we query the Gradle develocity to get flaky and then make
> > only those flaky
> > retryable in CI?
> >
> > This can work for existing flaky tests. We can query Develocity to find
> > flaky tests in the last N days
> > and run only those tests with retry. This is what I meant by "data
> driven"
> > for the quarantine. So, no need to track
> > "quarantined.txt" file separately -- we can derive this data at build
> time
> > from Develocity.
> >
> > However, this doesn't help with the newly added tests that introduce
> > flakiness. For this, we need some way
> > to detect when a new test has been added. Still thinking through this...
> >
> > -David
> >
> > On Thu, Sep 19, 2024 at 11:33 AM Chia-Ping Tsai <chia7...@gmail.com>
> > wrote:
> >
> > > hi David
> > >
> > > The two-tiered approach is interesting and I have questions similar to
> > > TengYao.
> > >
> > > BUT, go back to the usage of quarantine and isolation. It seems to me
> > they
> > > are used to make our CI not be noised by the flaky, right? If so, could
> > we
> > > query the Gradle develocity to get flaky and then make only those flaky
> > > retryable in CI? That means a non-flaky (stable) test must pass without
> > > retry.
> > >
> > > This approach is more simple (I guess), and it can isolate the flaky
> (by
> > > retry) from CI. If a flaky can't pass after retry, I feel it is a
> > critical
> > > failed test rather than just a flaky. On top of that, this approach
> does
> > > not need an extra file ("quarantined.txt") in git control and it does
> not
> > > need to change any code of test classes.
> > >
> > > Best,
> > > Chia-Ping
> > >
> > > TengYao Chi <kiting...@gmail.com> 於 2024年9月19日 週四 下午11:19寫道：
> > >
> > > > Hi David,
> > > >
> > > > Thanks for the explanation.
> > > >
> > > > I like this two-tiered approach, which gives us more flexibility to
> > > handle
> > > > flaky tests.
> > > >
> > > > The following is my understanding of how it works; please correct me
> if
> > > I'm
> > > > wrong:
> > > > If we adopt the two-tiered approach, the test might have two
> > > > states.(Isolated by developer, Quarantined automatically).
> > > > These two mechanisms are independent. We could manually remove a tag
> > > from a
> > > > test, but at the same time, it might still be quarantined.
> > > > I know the above situation might sound weird, but I just want to
> > > understand
> > > > how it would work.
> > > >
> > > > Best Regards,
> > > > TengYao
> > > >
> > > > David Arthur <mum...@gmail.com> 於 2024年9月19日 週四 下午10:07寫道：
> > > >
> > > > > Chia/TengYao/TaiJuWu, I agree that tags are a straightforward
> > approach.
> > > > In
> > > > > fact, my initial idea was to use tags as the isolation mechanism.
> > > > >
> > > > > Let me try to motivate the use of a text file a bit more.
> > > > >
> > > > > Consider the "new tests" scenario where a developer has added a new
> > > > > integration test. If we use annotations, this means someone (the
> > > original
> > > > > developer, or another committer) will need to raise a PR after a
> few
> > > days
> > > > > to remove the annotation (assuming the test was stable).
> Eventually,
> > I
> > > > was
> > > > > hoping to automate or partially automate this aspect of the system.
> > It
> > > > > seems simpler to write a script that modifies a plain text file
> > > compared
> > > > > with removing annotations in Java code.
> > > > >
> > > > > > we don't need to worry that "quarantined.txt" having out-of-date
> > test
> > > > > names
> > > > >
> > > > > This could be a problem, yes.
> > > > >
> > > > > ---
> > > > >
> > > > > Maybe we can consider a two-tiered approach here:
> > > > >
> > > > > Isolation (manual)
> > > > > * Test is marked with tag annotation
> > > > > * This is a permanent state until the developers think the test is
> > > > healthy
> > > > > again
> > > > > * These tests are run in a separate build step to not affect build
> > > > > outcomes, but gather data
> > > > >
> > > > >
> > > > > Quarantine (automated)
> > > > > * Tests leaving Isolation enter the Quarantine automatically
> > > > > * New integration tests enter the Quarantine automatically
> > > > > * Test stays in quarantine for a few days to evaluate
> > > > > * These tests are run in a separate build step to not affect build
> > > > > outcomes, but gather data
> > > > > * If all runs are passing, it leaves the quarantine
> > > > >
> > > > > I think with this approach, we can make the Quarantine fully
> > > data-driven
> > > > > and automated. Essentially, the build will query Develocity for
> flaky
> > > > test
> > > > > results from the last N days and run those tests separately.
> > > > >
> > > > >
> > > > > WDYT?
> > > > >
> > > > > On Thu, Sep 19, 2024 at 12:49 AM 吳岱儒 <tjwu1...@gmail.com> wrote:
> > > > >
> > > > > > Hi David,
> > > > > >
> > > > > > Thank you for KIP.
> > > > > >
> > > > > > Could we include percentages for each flaky test in
> > quarantined.txt?
> > > > This
> > > > > > would help us prioritize which tests to resolve first.
> > > > > >
> > > > > > Additionally, I would prefer to add a flaky (JUnit) tag to the
> > source
> > > > > code
> > > > > > so we can focus on these tests during development.
> > > > > >
> > > > > > Thanks,
> > > > > > TaiJuWu
> > > > > >
> > > > > >
> > > > > > On Thu, Sep 19, 2024 at 11:51 AM TengYao Chi <
> kiting...@gmail.com>
> > > > > wrote:
> > > > > >
> > > > > > > Hi David,
> > > > > > >
> > > > > > > Thanks for this great KIP.
> > > > > > >
> > > > > > > I really appreciate the goal of this KIP, which aims to
> stabilize
> > > the
> > > > > > build
> > > > > > > and improve our confidence in CI results.
> > > > > > > It addresses a real issue where we've become accustomed to
> seeing
> > > > > failed
> > > > > > > results from CI, and this is definitely not good for the Kafka
> > > > > community.
> > > > > > >
> > > > > > > I have a question regarding this KIP:
> > > > > > > It seems that we need to maintain the `quarantined.txt` files
> > > > manually,
> > > > > > is
> > > > > > > that correct?
> > > > > > > I'm thinking this could become an issue, especially with the
> > > planned
> > > > > > > removal of ZK in 4.0, which will undoubtedly bring many changes
> > to
> > > > our
> > > > > > > codebase.
> > > > > > > Given that, maintaining the `quarantined.txt` files might
> become
> > a
> > > > > pain.
> > > > > > > It would be nice if we could maintain it programmatically.
> > > > > > >
> > > > > > > Best Regards,
> > > > > > > TengYao
> > > > > > >
> > > > > > > Chia-Ping Tsai <chia7...@gmail.com> 於 2024年9月19日 週四 上午3:24寫道：
> > > > > > >
> > > > > > > > hi David
> > > > > > > >
> > > > > > > > The KIP is beautiful and I do love a rule which makes us
> handle
> > > > those
> > > > > > > flaky
> > > > > > > > seriously.
> > > > > > > >
> > > > > > > > Regarding the "JUnit Tags", it can bring some benefits to us.
> > > > > > > >
> > > > > > > > 1. we can retry only the tests having "flaky" annotation.
> Other
> > > > > > non-flaky
> > > > > > > > tests should not be retryable
> > > > > > > > 2. we don't need to worry that "quarantined.txt" having
> > > out-of-date
> > > > > > test
> > > > > > > > names
> > > > > > > > 3. we can require the flaky annotation must have jira link.
> > That
> > > > > means
> > > > > > > the
> > > > > > > > PR's author must create the jira link for the new flaky
> > > > > > > >
> > > > > > > > Also, we can add a gradle task to generate "quarantined.txt"
> > file
> > > > if
> > > > > > > needs.
> > > > > > > >
> > > > > > > > Best,
> > > > > > > > Chia-Ping
> > > > > > > >
> > > > > > > > David Arthur <mum...@gmail.com> 於 2024年9月19日 週四 上午12:02寫道：
> > > > > > > >
> > > > > > > > > Hello, Kafka community!
> > > > > > > > >
> > > > > > > > > Looking at the last 7 days of GitHub, we have 59 out of 64
> > > trunk
> > > > > > builds
> > > > > > > > > having flaky tests. Excluding timeouts (a separate issue),
> > > only 4
> > > > > > > builds
> > > > > > > > > out of the last 7 days have failed due to excess test
> > failures.
> > > > > This
> > > > > > is
> > > > > > > > > actually a slight improvement when compared with the last
> 28
> > > > days.
> > > > > > But
> > > > > > > > > still, this is obviously a bad situation to be in.
> > > > > > > > >
> > > > > > > > > We have previously discussed a few ideas to mitigate the
> > impact
> > > > > that
> > > > > > > > flaky
> > > > > > > > > tests have on our builds. For PRs, we are actually seeing a
> > lot
> > > > of
> > > > > > > > > successful status checks due to our use of the Develocity
> > test
> > > > > retry
> > > > > > > > > feature. However, the blanket use of "testRetry" is a bad
> > > > practice
> > > > > in
> > > > > > > > > my opinion. It makes it far too easy for us to ignore tests
> > > that
> > > > > are
> > > > > > > only
> > > > > > > > > occasionally flaky. It also applies to unit tests which
> > should
> > > > > never
> > > > > > be
> > > > > > > > > flaky.
> > > > > > > > >
> > > > > > > > > Another problem is that we are naturally introducing flaky
> > > tests
> > > > as
> > > > > > new
> > > > > > > > > features (and tests) are introduced. Similar to feature
> > > > > development,
> > > > > > it
> > > > > > > > > takes some time for tests to mature and stabilize -- tests
> > are
> > > > > code,
> > > > > > > > after
> > > > > > > > > all.
> > > > > > > > >
> > > > > > > > > I have written down a proposal for tracking and managing
> our
> > > > flaky
> > > > > > > > tests. I
> > > > > > > > > have written this as a KIP even though this is an internal
> > > > change.
> > > > > I
> > > > > > > did
> > > > > > > > so
> > > > > > > > > because I would like us to discuss, debate, and solidify a
> > plan
> > > > --
> > > > > > and
> > > > > > > > > ultimately vote on it. A KIP seemed like a good fit.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-1090+Flaky+Test+Management
> > > > > > > > >
> > > > > > > > > I have back-tested this strategy (as best as I can) to our
> > > trunk
> > > > > > builds
> > > > > > > > > from the last month using data from Develocity (i.e.,
> > > > > ge.apache.org
> > > > > > ).
> > > > > > > I
> > > > > > > > > looked at two scenarios. The first scenario was simply
> > > > quarantining
> > > > > > > tests
> > > > > > > > > with higher than 1% flaky failures, no test re-runs were
> > > > > considered.
> > > > > > > The
> > > > > > > > > second scenario extends the first by allowing up to 3 total
> > > flaky
> > > > > > > > failures
> > > > > > > > > from non-quarantined tests (tests with less than 1% total
> > > > > flakiness).
> > > > > > > > >
> > > > > > > > > Total builds: *238*
> > > > > > > > > Flaky/Failed builds: *228*
> > > > > > > > > Flaky builds scenario 1 (quarantine only): *40*
> > > > > > > > > Flaky builds scenario 2 (quarantine + retry): *3*
> > > > > > > > >
> > > > > > > > > In other words, we can tackle the worst flaky failures with
> > the
> > > > > > > > quarantine
> > > > > > > > > strategy as described in the KIP and handle the long tail
> of
> > > > flaky
> > > > > > > > failures
> > > > > > > > > with the Develocity retry plugin. If we only had 3 failing
> > > trunk
> > > > > > builds
> > > > > > > > per
> > > > > > > > > month to investigate, I'd say we were in pretty good shape
> :)
> > > > > > > > >
> > > > > > > > > Let me know what you think!
> > > > > > > > >
> > > > > > > > > Cheers,
> > > > > > > > > David A
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > > > --
> > > > > David Arthur
> > > > >
> > > >
> > >
> >
> >
> > --
> > David Arthur
> >
>
--
David Arthur
