[Feature flag] Rollout of `group_level_dependencies`

Summary

This issue is to rollout the feature on production, that is currently behind the group_level_dependencies feature flag.

Owners

Team: Threat Insights
Most appropriate slack channel to reach out to: #g_govern_threat_insights_tangerine
Best individual to reach out to: @zmartins
PM: @abellucci

Stakeholders

Testing

It was identified that the Namespace Projects Finder is at risk of performance issues when interacting with namespaces with significant child and project counts inside. We need to carefully test the possible impact of rolling out this feature flag to GitLab and monitor performance carefully to ensure that we do not negatively impact the platform stability.

Kibana dashboard or additional sisense metrics should be implemented and ready to monitor the execution times of the finder before rollout of the FF is begun.

Aspects that should be improved or mitigated to not over-consume database query buffers:

Feature description	Status	Related issues/MRs	Related files
Project search with `sbom_component_id`	workflowcomplete	!125593 (merged), https://gitlab.com/gitlab-org/gitlab/-/issues/417483#note_1465951762	https://gitlab.com/gitlab-org/gitlab/-/blob/5fde763a8a3af99fa100f35b68bdf3f1d201bf2f/ee/app/models/ee/project.rb#L319, https://gitlab.com/gitlab-org/gitlab/-/blob/5fde763a8a3af99fa100f35b68bdf3f1d201bf2f/ee/app/finders/ee/namespaces/projects_finder.rb#L27
Sorting and Filtering with `sbom_source_id`	workflowcomplete	#415665 (closed)	https://gitlab.com/gitlab-org/gitlab/-/blob/c43f11624d4456506831d6f93534ce98fbe4bb37/ee/app/models/sbom/occurrence.rb#L29-35
Location search based on `sbom_source.source->'input_file'->>'path'`	workflowcomplete	!126541 (merged)	https://gitlab.com/gitlab-org/gitlab/-/blob/c43f11624d4456506831d6f93534ce98fbe4bb37/ee/app/models/sbom/occurrence.rb#L41-46

Testing groups for the performance related issues

Using the highest namespace id will potentially stress test more as other nest groups and projects will also be included in comparison to the original namespace id.

Sorted by the number of sbom_occurrences

select namespaces.traversal_ids[1] as highest_namespace_id, tt.original_namespace_id, tt.project_count, tt.occurrence_count
from namespaces
inner join (
  select projects.namespace_id as original_namespace_id, count(t.project_id) as project_count, SUM(t.occurrence_count) as occurrence_count
  from projects
  inner join (
    select project_id, count(id) as occurrence_count
    from sbom_occurrences
    group by project_id
  ) t on t.project_id = projects.id
  group by projects.namespace_id
) tt on tt.original_namespace_id = namespaces.id
where namespaces.type = 'Group'
order by occurrence_count desc
limit 10;

 highest_namespace_id | original_namespace_id | project_count | occurrence_count
----------------------+-----------------------+---------------+------------------
              5778500 |              33604909 |           580 |           140272
              6086725 |               8665615 |            88 |           115650
              4635105 |              12906062 |            52 |           103950
              2369324 |               2369324 |            48 |           103722
              9758595 |              10219432 |            55 |            92534
             14150259 |              52604711 |            59 |            84728
              5669232 |               5940393 |           110 |            79709
              2138622 |               3696834 |            51 |            69198
             10433603 |              65488185 |            26 |            60760
             12732159 |              13465281 |            41 |            59488
(10 rows)

Sorted by the number of projects

> select namespaces.traversal_ids[1] as highest_namespace_id, tt.original_namespace_id, tt.project_count, tt.occurrence_count
from namespaces
inner join (
  select projects.namespace_id as original_namespace_id, count(t.project_id) as project_count, SUM(t.occurrence_count) as occurrence_count
  from projects
  inner join (
    select project_id, count(id) as occurrence_count
    from sbom_occurrences
    group by project_id
  ) t on t.project_id = projects.id
  group by projects.namespace_id
) tt on tt.original_namespace_id = namespaces.id
where namespaces.type = 'Group'
order by project_count desc
limit 10;

 highest_namespace_id | original_namespace_id | project_count | occurrence_count
----------------------+-----------------------+---------------+------------------
              5778500 |              33604909 |           580 |           140272
               478651 |              62067373 |           201 |            46827
             12854557 |              60191330 |           151 |              960
              5000222 |              11210029 |           128 |             9480
              5669232 |               5940393 |           110 |            79709
              9758595 |              13389416 |           104 |             4262
              5942816 |               6186706 |           102 |            27833
              6086725 |               8665615 |            88 |           115650
              7308774 |              13222172 |            82 |            19373
             60682937 |              63077381 |            72 |            13682
(10 rows)

Complexity within the traversal_ids

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{6543}');
 count
-------
  1683

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{12854557}');
 count
-------
  1439

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{5778500}');
 count
-------
  1139

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{7308774}');
 count
-------
  1129

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{5000222}');
 count
-------
   782

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{9758595}');
 count
-------
   778

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{5942816}');
 count
-------
   300

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{5669232}');
 count
-------
   281

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{6086725}');
 count
-------
   124

SELECT count(namespaces.traversal_ids) FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND traversal_ids @> ('{60682937}');
 count
-------
   109

Once ready:

A database maintainer should review that all possible mitigations and remediations have been appropriately applied.

Expectations

What are we expecting to happen?

Dependency list will be available on group level.

When is the feature viable?

N/A

What might happen if this goes wrong?

Turning off the feature flag should be all that is required.

What can we monitor to detect problems with this?

Consider mentioning checks for 5xx errors or other anomalies like an increase in redirects (302 HTTP response status)

What can we check for monitoring production after rollouts?

Consider adding links to check for Sentry errors, Production logs for 5xx, 302s, etc.

Rollout Steps

Note: Please make sure to run the chatops commands in the slack channel that gets impacted by the command.

Rollout on non-production environments

Verify the MR with the feature flag is merged to master.
Verify that the feature MRs have been deployed to non-production environments with:
- /chatops run auto_deploy status https://gitlab.com/gitlab-org/gitlab/-/merge_requests/129260
Enable the feature globally on non-production environments.
- /chatops run feature set group_level_dependencies true --dev --staging --staging-ref
- If the feature flag causes QA end-to-end tests to fail:
  - Disable the feature flag on staging to avoid blocking deployments.
Verify that the feature works as expected. Posting the QA result in this issue is preferable. The best environment to validate the feature in is staging-canary as this is the first environment deployed to. Note you will need to make sure you are configured to use canary as outlined here when accessing the staging environment in order to make sure you are testing appropriately.

For assistance with QA end-to-end test failures, please reach out via the #quality Slack channel. Note that QA test failures on staging-ref don't block deployments.

Specific rollout on production

For visibility, all /chatops commands that target production should be executed in the #production slack channel and cross-posted (with the command results) to the responsible team's slack channel (#g_TEAM_NAME).

Ensure that the feature MRs have been deployed to both production and canary.
- /chatops run auto_deploy status https://gitlab.com/gitlab-org/gitlab/-/merge_requests/129260
Depending on the type of actor you are using, pick one of these options:
- If you're using project-actor, you must enable the feature on these entries:
  - /chatops run feature set --project=gitlab-org/gitlab,gitlab-org/gitlab-foss,gitlab-com/www-gitlab-com group_level_dependencies true
- If you're using group-actor, you must enable the feature on these entries:
  - /chatops run feature set --group=gitlab-org,gitlab-com <feature-flag-name> true
- If you're using user-actor, you must enable the feature on these entries:
  - /chatops run feature set --user=<your-username> group_level_dependencies true
Verify that the feature works on the specific entries. Posting the QA result in this issue is preferable.

Preparation before global rollout

Set a milestone to the rollout issue to signal for enabling and removing the feature flag when it is stable.
Check if the feature flag change needs to be accompanied with a change management issue. Cross link the issue here if it does.
Ensure that you or a representative in development can be available for at least 2 hours after feature flag updates in production. If a different developer will be covering, or an exception is needed, please inform the oncall SRE by using the @sre-oncall Slack alias.
Ensure that documentation has been updated (More info).
Leave a comment on the feature issue announcing estimated time when this feature flag will be enabled on GitLab.com.
Ensure that any breaking changes have been announced following the release post process to ensure GitLab customers are aware.
Notify #support_gitlab-com and your team channel (more guidance when this is necessary in the dev docs).
Ensure that the feature flag rollout plan is reviewed by another developer familiar with the domain.

Global rollout on production

Incrementally roll out the feature.
- Between every step wait for at least 15 minutes and monitor the appropriate graphs on https://dashboards.gitlab.net.
- If the feature flag in code has an actor, perform actor-based rollout.
  - /chatops run feature set group_level_dependencies <rollout-percentage> --actors
- If the feature flag in code does NOT have an actor, perform time-based rollout (random rollout).
  - /chatops run feature set group_level_dependencies <rollout-percentage> --random
- Enable the feature globally on production environment.
  - /chatops run feature set group_level_dependencies true
Observe appropriate graphs on https://dashboards.gitlab.net and verify that services are not affected.
Leave a comment on the feature issue announcing that the feature has been globally enabled.
Wait for at least one day for the verification term.

(Optional) Release the feature with the feature flag

If you're still unsure whether the feature is deemed stable but want to release it in the current milestone, you can change the default state of the feature flag to be enabled. To do so, follow these steps:

WARNING: This approach has the downside that it makes it difficult for us to clean up the flag. For example, on-premise users could disable the feature on their GitLab instance. But when you remove the flag at some point, they suddenly see the feature as enabled and they can't roll it back to the previous behavior. To avoid this potential breaking change, use this approach only for urgent matters.

Release the feature

After the feature has been deemed stable, the clean up should be done as soon as possible to permanently enable the feature and reduce complexity in the codebase.

You can either create a follow-up issue for Feature Flag Cleanup or use the checklist below in this same issue.

Rollback Steps

This feature can be disabled by running the following Chatops command:

/chatops run feature set group_level_dependencies false

Edited Sep 06, 2023 by Zamir Martins