GPRD chunk gitlab-org/search-team/test-public-project into a separate zoekt index

Production Change

Change Summary

As part of supporting large namespaces with zoekt, we'd like to "chunk" a low risk repository into a separate zoekt index. See related issue: gitlab-org/gitlab#471638 (closed)

Change Details

1. Services Impacted - zoekt
2. Change Technician - @johnmason
3. Change Reviewer - @dgruzd
4. Time tracking - 1h
5. Downtime Component - N/A

Set Maintenance Mode in GitLab

If your change involves scheduled maintenance, add a step to set and unset maintenance mode per our runbooks. This will make sure SLA calculations adjust for the maintenance period.

Detailed steps for the change

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 1h

• Set label changein-progress /label ~change::in-progress
• Execute console steps in staging for https://staging.gitlab.com/gitlab-org/dgruzd-search-test/test-project-1
• Add an incremental change by updating a file with a keyword like 20240725
• Verify search results are working for group search in staging
• Execute console steps in production for https://gitlab.com/gitlab-org/search-team/test-public-project
• Add an incremental change by updating a file with a keyword like 20240725
• Verify search results are working for production
• Set label changecomplete /label ~change::complete

Rollback

Rollback steps - steps to be taken in the event of a need to rollback this change

Estimated Time to Complete (mins) - 1h

• Destroy the zoekt repository
• Destroy the additional zoekt index
• Force reindexing for the affected project
• Set label changeaborted /label ~change::aborted

Monitoring

Key metrics to observe

The biggest thing to monitor is whether incremental changes are searchable.

• Metric: Zoekt indexing failures
  • Location: https://log.gprd.gitlab.net/app/dashboards#/view/1a3be100-7fa4-11ee-ac5b-8f88ebd04638?_g=(refreshInterval:(pause:!t,value:60000),time:(from:now-1d,to:now))
  • What changes to this metric should prompt a rollback: If there is large spike in indexing failures with affected project, or if the project is no longer searchable.

Change Reviewer checklist

C4 C3 C2 C1:

• Check if the following applies:
  • The scheduled day and time of execution of the change is appropriate.
  • The change plan is technically accurate.
  • The change plan includes estimated timing values based on previous testing.
  • The change plan includes a viable rollback plan.
  • The specified metrics/monitoring dashboards provide sufficient visibility for the change.

C2 C1:

• Check if the following applies:
  • The complexity of the plan is appropriate for the corresponding risk of the change. (i.e. the plan contains clear details).
  • The change plan includes success measures for all steps/milestones during the execution.
  • The change adequately minimizes risk within the environment/service.
  • The performance implications of executing the change are well-understood and documented.
  • The specified metrics/monitoring dashboards provide sufficient visibility for the change.
    • If not, is it possible (or necessary) to make changes to observability platforms for added visibility?
  • The change has a primary and secondary SRE with knowledge of the details available during the change window.
  • The change window has been agreed with Release Managers in advance of the change. If the change is planned for APAC hours, this issue has an agreed pre-change approval.
  • The labels blocks deployments and/or blocks feature-flags are applied as necessary.

Change Technician checklist

• Check if all items below are complete:
  • The change plan is technically accurate.
  • This Change Issue is linked to the appropriate Issue and/or Epic
  • Change has been tested in staging and results noted in a comment on this issue.
  • A dry-run has been conducted and results noted in a comment on this issue.
  • The change execution window respects the Production Change Lock periods.
  • For C1 and C2 change issues, the change event is added to the GitLab Production calendar.
  • For C1 and C2 change issues, the SRE on-call has been informed prior to change being rolled out. (In #production channel, mention @sre-oncall and this issue and await their acknowledgement.)
  • For C1 and C2 change issues, the SRE on-call provided approval with the eoc_approved label on the issue.
  • For C1 and C2 change issues, the Infrastructure Manager provided approval with the manager_approved label on the issue.
  • Release managers have been informed prior to any C1, C2, or blocks deployments change being rolled out. (In #production channel, mention @release-managers and this issue and await their acknowledgment.)
  • There are currently no active incidents that are severity1 or severity2
  • If the change involves doing maintenance on a database host, an appropriate silence targeting the host(s) should be added for the duration of the change.