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Debugging Failing Tests and Test Pipelines

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  5. Debugging Failing Tests and Test Pipelines

Overview

These guidelines are intended to help you to investigate end-to-end test pipeline failures so that they can be properly addressed. This will involve analyzing each failure and creating an issue to report it. It might also involve fixing tests, putting them in quarantine, or reporting bugs in the application.

The Pipeline triage DRI is responsible for analyzing and debugging test pipeline failures. Please refer to the Quality Department pipeline triage rotation schedule to know who the current DRI is.

Scheduled QA test pipelines

The test pipelines run on a scheduled basis, and their results are posted to Slack. The following are the QA test pipelines that are monitored every day.

Environment Tests type Schedule Slack channel
Production Smoke and Reliable Every 2 hours. #qa-production
Production Full Every 12 hours. #qa-production
Canary Smoke and Reliable Every 2 hours, and after each deployment to Canary. The bi-hourly schedule is useful to catch failures introduced by a configuration change. #qa-production
Staging Smoke and Reliable Every 2 hours, and after each deployment to Staging. The bi-hourly schedule is useful to catch failures introduced by a configuration change. #qa-staging
Staging Smoke and Reliable (No Admin) Every 2 hours. This is useful to catch issues when requires_admin tag is missed. #qa-staging
Staging^ Full, Orchestrated After each deployment to Staging. #qa-staging
Staging Geo Daily at 14:00 UTC. #qa-staging
CustomersDot Staging Full After each deployment to CustomersDot Staging #qa-staging #s_fulfillment_status
Preprod Smoke, Reliable After deployment to preprod during Security and Patch releases #qa-preprod
Nightly packages Full Daily at 4:00 am UTC. #qa-nightly
GitLab master Full When the package-and-qa job executes from a scheduled pipeline every 2 hours. #qa-master
GitLab FOSS master Full When the package-and-qa job executes from a scheduled pipeline every 2 hours. #qa-master

^Test pipelines also run against an Omnibus-GitLab Docker image that reflects the current release on staging.com. These are referred to in notifications as dev.gitlab.org:5005/gitlab/omnibus-gitlab/gitlab-ee:xxx

For each pipeline there is a notification of success or failure (except for master pipelines, which only report failures). If there's a failure, we use emoji to indicate the state of its investigation:

How to triage a QA test pipeline failure

The general triage steps are:

After triaging failed tests, possible follow up actions are:

Report the failure

Your priority is to make sure we have an issue for each failure, and to communicate the status of its investigation and resolution. When there are multiple failures to report, consider their impact when deciding which to report first. See the pipeline triage reponsilibities for further guidance.

If there are multiple failures we recommend that you identify whether each one is new or old (and therefore already has an issue open for it). For each new failure, open an issue that includes only the required information. Once you have opened an issue for each new failure you can investigate each more thoroughly and act on them appropriately, as described in later sections.

The reason for reporting all new failures first is to allow faster discovery by engineers who might find the test failing in their own merge request test pipeline. If there is no open issue about that failure, the engineer will have to spend time trying to figure out if their changes caused it.

Known failures should be linked to the current pipeline triage report. However, issues can be opened by anyone and are not linked automatically, so be sure to confirm there is no existing issue before creating one.

  1. Search for existing issues that have already been created with the failure::* label. By order of likelihood:
    1. failure::investigating
    2. failure::test-environment
    3. failure::broken-test
    4. failure::flaky-test
    5. failure::stale-test
  2. If the issue has already been reported please use the existing issue to track the latest status.
  3. If there is no existing issue for the failure, please create an issue using one of classification labels via the steps below.

In the relevant Slack channel:

  1. Apply the :eyes: emoji to indicate that you're investigating the failure(s).
  2. If there's a system failure (e.g., Docker or runner failure), retry the job and apply the :retry: emoji. Read below for examples of system failures.
  3. If an issue exists, add a :fire_engine: emoji. It can be helpful to reply to the failure notification with a link to the issue(s), but this isn't always necessary, especially if the failures are the same as in the previous pipeline and there are links there.
  4. If you create a new issue, add a :boom: emoji.

Create an issue

Please use this step if there are no issues created to capture the failure. If there is already an issue please skip this step.

  1. Create an issue for the test or system failure (if retrying the job does not resolve the latter) in https://gitlab.com/gitlab-org/gitlab/issues using the QA failure template. For failures in CustomersDot tests, open an issue in CustomersDot project.
  2. In the relevant Slack channel, add the :boom: emoji and reply to the failure notification with a link to the issue.
  3. Add the issue as a related issue to the current pipeline triage report.

Review the failure logs

The aim of this step is to understand the failure. The results of the investigation will also let you know what to do about the failure. Update the failure issue with any findings from your review.

The following can help with your investigation:

Log or artifact Notes
Stack trace Shown in the job's log; the starting point for investigating the test failure
Screenshots and HTML captures Available for download in the job's artifact for up to 1 week after the job run
QA Logs Included in the job's artifact; valuable for determining the steps taken by the tests before failing
Sentry logs (Staging, Preprod, Production) If staging, preprod or production tests fail due to a server error, there should be a record in Sentry. For example, you can search for all unresolved staging errors linked to the gitlab-qa user with the query is:unresolved user:"username:gitlab-qa". However, note that some actions aren't linked to the gitlab-qa user, so they might only appear in the full unresolved list.
Kibana logs (Staging, Production) Various application logs are sent to Kibana, including Rails, Postgres, Sidekiq, and Gitaly logs

Investigate the root cause

Depending on your level of context for the test and its associated setup, you might feel comfortable investigating the root cause on your own, or you might get help from other SETs right away.

When investigating on your own, we suggest spending at most 20-30 minutes actively trying to find the root cause (this excludes time spent reporting the failure, reviewing the failure logs, or any test setup and pipeline execution time). After that point, or whenever you feel out of ideas, we recommend asking for help to unblock you.

Note: It is not recommended to log in via gitlab-qa and all the other bot accounts on Canary/Production as they have Admin privileges. If it is really needed to log in with these accounts, please give a quick heads-up in #security-department that someone is logging into the bot and tag @sirt-team for awareness.

Run the test against your GDK

You can run the test (or perform the test steps manually) against your local GitLab instance to see if the failure is reproducible. For example:

CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://localhost:3000 qa/specs/features/browser_ui/1_manage/project/create_project_spec.rb

Orchestrated tests are excluded by default. To run them, use -- --tag orchestrated before your file name. For example:

CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://localhost:3000 -- --tag orchestrated qa/specs/features/browser_ui/1_manage/project/create_project_spec.rb

Run the test against a GitLab Docker container

You can also use the same Docker image (same sha256 hash) as the one used in the failing job to run GitLab in a container on your local. In the logs of the failing job, search for Downloaded newer image for gitlab/gitlab-ce:nightly or Downloaded newer image for gitlab/gitlab-ee:nightly and use the sha256 hash just above that line.

To run GitLab in a container on your local, the docker command similar to the one shown in the logs can be used. E.g.:

docker run --publish 80:80 --name gitlab --net test --hostname localhost gitlab/gitlab-ce:nightly@sha256:<hash>

You can now run the test against this Docker instance. E.g.:

CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://localhost qa/specs/features/browser_ui/1_manage/project/create_project_spec.rb

Run the tests against CustomersDot staging environment

To run CustomersDot E2E tests locally against staging environment, you will need to clone CustomersDot project, switch to qa directory, and then run

STAGING=1 CP_ADMIN_TOKEN=<TOKEN> GL_ADMIN_TOKEN=<TOKEN> bundle exec rspec spec/ui/purchase/purchase_plan_spec.rb

Note - Token value can be found in GitLab-QA Vault. For details on running tests locally with more options, please refer to CustomersDot README doc

Tips for running tests locally

Checking Docker images

Sometimes tests may fail due to an outdated Docker image. To check if that's the case, follow the instructions below to see if specific merged code is available in a Docker image.

Checking test code (QA image)

If you suspect that certain test is failing due to the gitlab/gitlab-{ce|ee}-qa image being outdated, follow these steps:

  1. Locally, run docker run -it --entrypoint /bin/sh gitlab/gitlab-ce-qa:latest to check for GitLab QA CE code, or docker run -it --entrypoint /bin/sh gitlab/gitlab-ee-qa:latest to check for GitLab QA EE code
  2. Then, navigate to the qa directory (cd /home/qa/qa)
  3. Finally, use cat to see if the code you're looking for is available in certain file (e.g., cat page/project/issue/show.rb)

Note if you need to check in another tag (e.g., nightly), change it in one of the scripts of step 1 above.

Checking application code
  1. Locally, run docker run -it --entrypoint /bin/sh gitlab/gitlab-ce:latest to check for GitLab CE code, or docker run -it --entrypoint /bin/sh gitlab/gitlab-ee:latest to check for GitLab EE code
  2. Then, navigate to the gitlab-rails directory (cd /opt/gitlab/embedded/service/gitlab-rails/)
  3. Finally, use cat to see if the code you're looking for is available or not in a certain file (e.g., cat public/assets/issues_analytics/components/issues_analytics-9c3887211ed5aa599c9eea63836486d04605f5dfdd76c49f9b05cc24b103f78a.vue.)

Note if you want to check another tag (e.g., nightly) change it in one of the scripts of step 1 above.

Checking application version has the specific MR
  1. Find the version which GitLab application is running on. In the failing job logs, search for docker pull dev.gitlab.org:5005/gitlab/omnibus-gitlab/gitlab-ee-qa and use the version specified after gitlab-ee-qa:.
    • For nightly the approach above won't work. There are two ways for finding the commit version of nightly:
      • Run the nightly image on local, sign-in as admin and navigate to /help page or call the /api/v4/version API.
      • Search for the commit in the omnibus-gitlab pipeline that built the last nightly. Jobs that build nightly have bundle exec rake docker:push:nightly command in the Docker-branch job of the Package-and-image stage. Once you find the latest pipeline, search for gitlab-rails under build-component_shas in any job under the Gitlab_com:package stage. For example, in this Ubuntu-16.04-branch job, the commit SHA for gitlab-rails is 32e76bc4fb02a615c2bf5a00a8fceaee7812a6bd.
  2. Open commits list for the specific version:
    • If version format is like a commit SHA, for example gitlab-ee-qa:13.10-4b373026c98, navigate to https://gitlab.com/gitlab-org/gitlab/-/commits/<commit_SHA> page, in our example the commit SHA is 4b373026c98.
    • If version format is like a tag, for example 13.10.0-rc20210223090520-ee, navigate to https://gitlab.com/gitlab-org/gitlab/-/commits/v<tag> page, in our example the tag is 13.10.0-rc20210223090520-ee.
    • If page above returns 404 error, check if the version exists in GitLab Security repo in case there is a security release.
  3. Check if the MR that you were searching for is in this version.
    • Note the branch name of the MR.
    • Search the commits from Step 2 by the branch name.
      • If the commit is found, the MR is in this version. For example.
      • If no results, the MR is not in this version. For example.

Classify and triage the test failure

The aim of this step is to categorize the failure as either a stale test, a bug in the test, a bug in the application code, or a flaky test.

We use the following labels to capture the cause of the failure.

Note: It might take a while for a fix to propagate to all environments. Be aware that a new failure could be related to a recently-merged fix that hasn't made it to the relevant environment yet. Similarly, if a known failure occurs but the test should pass because a fix has been merged, verify that the fix has been deployed to the relevant environment before attempting to troubleshoot further.

Stale test due to application change

The failure was caused by a change in the application code and the test needs to be updated.

See Quarantining Tests

Bug in the test

The failure was caused by a bug in the test code itself, not in the application code.

See Quarantining Tests

Bug in the application

The failure was caused by a bug in the application code.

Note: GitLab maintains a daily deployment cadence so a breaking change in master reaches Canary and Production fast. Please communicate broadly to ensure that the corresponding Product Group is aware of the regression and action is required. If the bug is qualified for dev escalation (example: priority::1/severity::1 issue that blocks the deployment process), consider involving On-call Engineers in the #dev-escalation channel. To find out who’s on-call follow the links in the channel subject line.

To find the appropriate team member to cc, please refer to the Organizational Chart. The Quality Engineering team list and DevOps stage group list might also be helpful.

See Quarantining Tests

Flaky Test

The failure is due to flakiness in the test itself.

Flakiness can be caused by a myriad of problems. Examples of underlying problems that have caused us flakiness include:

For more details, see the list with example issues in our Testing standards and style guidelines section on Flaky tests.

See Quarantining Tests

Failure due to test environment

The failure is due external factors outside the scope of the test. This could be due to environments, deployment hang-ups, or upstream dependencies.

A job may fail due to infrastructure or orchestration issues that are not related to any specific test. In some cases these issues will fail a job before tests are ever executed. Some examples of non-test related failures include:

Notify relevant groups about the failure

If the failure is in a smoke or a reliable test, it will block deployments. Please inform the release managers of the root cause and if a fix is in progress by Quality. On GitLab.com you can use @gitlab-org/release/managers. In Slack you can use @release-managers.

Please also raise awareness by looping in the appropriate team members from the product group, such as SET or EM. You may also want to post to Quality's Slack channel, #quality, depending on the impact of the failure.

Following up on test failures

Fixing the test

If you've found that the test is the cause of the failure (either because the application code was changed or there's a bug in the test itself), it will need to be fixed. This might be done by another SET or by yourself. However, it should be fixed as soon as possible. In any case, the steps to follow are as follows:

If the test was flaky:

Note The number of passes needed to be sure a test is stable is just a suggestion. You can use your judgement to pick a different threshold.

If the test was in quarantine, remove it from quarantine.

Quarantining Tests

Note We should be very strict about quarantining tests. Quarantining a test is very costly and poses a higher risk because it allows tests to fail without blocking the pipeline, which could mean we miss new failures.

The aim of quarantining a test is not to get back a green pipeline, but rather to reduce the noise (due to constantly failing tests, flaky tests, and so on) so that new failures are not missed. If you're unsure about quarantining a test ask for help in the#quality Slack channel, and then consider adding to the list of examples below to help future pipeline triage DRIs.

Examples of when to quarantine a test:

Examples of when not to quarantine a test:

Note The time limit for the fix is just a suggestion. You can use your judgement to pick a different threshold.

To quarantine a test:

Note If the example has a before hook, the quarantine metadata should be assigned to the outer context to avoid running the before hook.

To be sure that the test is quarantined quickly, ask in the #quality Slack channel for someone to review and merge the merge request, rather than assigning it directly.

Here is an example quarantine merge request.

Quarantined Test Types

If a test is placed under quarantine, it is important to specify why. By specifying a quarantine type we can see quickly the reason for the quarantine.

The report accepts custom quarantine types, but we follow the below guidelines for the most commonly recurring reasons.

Quarantine Type Requires :issue? Description
:flaky Yes This test fails intermittently
:bug Yes This test is failing due to an actual bug in the application
:waiting_on Yes This test is quarantined temporarily due to an issue or MR that is a prerequisite for this test to pass
:investigating No This test is a :flaky test but it might be blocking other MRs and so should be quarantined while it's under investigation
:stale No This test is outdated due to a feature change in the application and must be updated to fit the new changes

Note Be sure to attach an issue to the quarantine metadata if there is a related issue or merge request for maximum visibility

Examples

it 'is flaky', quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/12345'
it 'is flaky', quarantine: { issue: 'https://gitlab.com/gitlab-org/gitlab/issues/12345', type: :flaky }
it 'is due to a bug', quarantine: {
                        issue: 'https://gitlab.com/gitlab-org/gitlab/issues/12345',
                        type: :bug
                      }
it 'is being worked on', quarantine: { type: :investigating }
context 'when these tests rely on another MR', quarantine: {
                                                 type: :waiting_on,
                                                 issue: 'https://gitlab.com/gitlab-org/gitlab/merge_requests/12345'
                                               }

Nested contexts

You should apply the quarantine tag to the outermost describe/context block that has tags relevant to the test being quarantined.

# Good
RSpec.describe 'Plan', :smoke, quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/12345' do
  describe 'Feature' do
    before(:context) do
      # This before(:context) block will only be executed in smoke quarantine jobs
    end
  end
end

# Bad
RSpec.describe 'Plan', :smoke do
  describe 'Feature', quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/12345' do
    before(:context) do
      # This before(:context) block could be mistakenly executed in quarantine jobs that _don't_ have the smoke tag
    end
  end
end

Dequarantining Tests

Failing to dequarantine tests periodically reduces the effectiveness of the test suite. Hence, the tests should be dequarantined on or before the due-date mentioned in the corresponding issue.

Before dequarantining a test:

To dequarantine a test:

As with quarantining a test, you can ask in the #quality Slack channel for someone to review and merge the merge request, rather than assigning it.

Re-evaluating tests

If the due date of a failing test issue is reached, you should re-evaluate if the failing test should really be covered at the end-to-end test level, or if it should be covered in a lower level of the testing levels pyramid.

If you decide to delete the test, open a merge request to delete it and close the test failure issue. In the MR description or comment, mention the stable counterpart SET for the test's stage for their awareness. Then open a new issue to cover the test scenario in a different test level.

If you decide the test is still valuable but don't want to leave it quarantined, you could replace :quarantine with :skip, which will skip the test entirely (i.e., it won't run even in jobs for quarantined tests). That can be useful when you know the test will continue to fail for some time (e.g., at least the next milestone or two).

Training Videos

Two videos walking through the triage process were recorded and uploaded to the GitLab Unfilitered YouTube channel.

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