2023-09-26 0830 UTC: Enable the Feature Flag (optimize_find_routable) at 0.1%
Production Change
Change Summary
This is a change for the GPRD Environment
We introduced a new implementation of the method Routable.find_by_full_path
, which is used by both Project
and Group
and we want to enable it for %0.1
of the requests (percentage of actors) on GPRD
. ChatOPS doesn't allow percentages lower than 1%
.
This Feature Flag was enabled on GSTG
on 25th September, first at 50% of the requests then fully at 100%. See gitlab-org/gitlab#425859 (comment 1576422048)
A previous similar feature flag optimize_routable
was enabled, but caused an S1 incident, that's why we want to enable this feature flag at much lower percentage. But the difference is that this feature flag will return the same consistent value within the lifetime of a request or a sidekiq job.
Change Details
- Services Impacted - Rails Web Services, Rails API, Sidekiq
- Change Technician - @ahmadsherif
-
Change Reviewer -
@ayeung
- Time tracking - Maximum 20 Minutes
- Downtime Component - No downtime is needed
Set Maintenance Mode in GitLab
- Maintenance Mode is not needed
Detailed steps for the change
Change Steps - steps to take to execute the change
Estimated Time to Complete (mins) - {15 Minutes}
-
Set label changein-progress /label ~change::in-progress
-
Log in into a GPRD
Rails Console with write access. -
Run Feature.enable_percentage_of_actors(:optimize_find_routable, 0.1)
-
Verify Production Logs optimize_find_routable:1 that the feature flag is enabled for at least some requests -
Monitor for any adverse effects for 10 Minutes -
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) - {5 Minutes}
-
From the same Rails Console run Feature.disable(:optimize_find_routable)
-
Set label changeaborted /label ~change::aborted
Monitoring
Key metrics to observe
- Production Logs InvalidStatement Errors
- Production Logs optimize_find_routable:1
- Production Logs with status code optimize_find_routable:1
- https://dashboards.gitlab.net/d/general-triage/general-platform-triage?orgId=1
Change Reviewer checklist
-
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.
-
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.