Container Registry: Apply post-deployment migrations in v3.82.0

Production Change

Change Summary

Request to manually apply 1 new post-deployment migration(s) included in the container registry v3.82.0 in pre, gstg, and gprd environments.

These new post-deployment migrations are related to refactor(database): remove migration_status column (gitlab-org/container-registry#996 - closed). The change was introduced and reviewed/approved by the Database team in gitlab-org/container-registry!1404 (merged).

Please read the Context section in this runbook to understand why manual intervention is currently needed.

Target post-deployment migrations:

• 20230822130421_drop_repositories_migration_columns: Drops the unused migration_status and migration_error columns from the repositories table.

Change Details

1. Services Impacted - ServiceContainer Registry
2. Change Technician - @jennykim-gitlab
3. Change Reviewer - @ahyield
4. Time tracking - 5 minutes (sum of all environments)
5. Downtime Component - NA

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

Repeat for each environment:

• pre Ready
• gstg Ready
• gprd Ready

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 5 minutes

• Set label changein-progress /label ~change::in-progress
• Proceed as described here. The SQL statements in the pending migrations are expected to complete really fast across all envs, so there should be no need for the additional steps in described in long-running migrations.
• Set label changecomplete /label ~change::complete

Rollback

NA. In the worst-case scenario, the columns drop fails and aborts the execution. The only side effect is that we would have to repeat this change after a fix was released.

Monitoring

Key metrics to observe

• Metric: Postgres CPU Usage
  • Location: https://dashboards.gitlab.net/d/patroni-registry-main/patroni-registry-overview?orgId=1&viewPanel=92
  • What changes to this metric should prompt a rollback: If an abnormal CPU usage spike is observed around the execution of this change, please abort the ongoing CLI command.

There are no relevant application metrics to observe here as the dropped columns are no longer used.

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.