2023-09-25: Cutover 100% of codesuggestions.gitlab.com traffic to new runway infra
Production Change
Change Summary
Change 100% of codesuggestions.gitlab.com traffic to runway architecture
As part of epic &1064 (closed) we have been in the process of migrating the ai-gateway (formerly model-gateway) service that powers codesuggestions.gitlab.com from running on top of legacy Kubernetes infrastructure (currently unmanaged) to running on top of the new Runway platform.
The infrastructure setup in front of codesuggestions.gitlab.com is a cloudflare load balancer with backends set to the old legacy infrastructure and new runway infrastructure. Currently 70% traffic goes to the legacy infrastructure, and this change request is to finish cutting over all traffic to the new runway infra.
Change Details
- Services Impacted - codesuggestions.gitlab.com
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Change Technicians -
@alejandro
,@cfeick
- Change Reviewer - @igorwwwwwwwwwwwwwwwwwwww
- Time tracking - 120 minutes
- Downtime Component - none
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) - 60
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Set label changein-progress /label ~change::in-progress
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Merge to set traffic cutover at 50% https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt/-/merge_requests/6783 -
Monitor for at least 2 hours -
Merge to set traffic cutover at 80% https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt/-/merge_requests/6784 -
Monitor for at least 2 hours -
Merge to set traffic cutover at 100% https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt/-/merge_requests/6785 -
Monitor dashboards and metrics for 60 minutes to ensure no changes -
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) - 60
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Create revert MR for https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt/-/merge_requests/6705 and merge/apply -
Monitor dashboards and metrics for 60 minutes to ensure any abnormalities return to normal -
Set label changeaborted /label ~change::aborted
Monitoring
Key metrics to observe
Runway Container CPU Utilization
- Metric: Runway Container CPU Utilization
- Locations:
- What changes to this metric should prompt a rollback: 80% saturation for sustained duration. Lower is better.
- What steps to take for mitigation: Configure CPU limits: https://cloud.google.com/run/docs/configuring/services/cpu.
Runway Container Instance Utilization
- Metric: Runway Container Instance Utilization
- Locations:
- What changes to this metric should prompt a rollback: 80% saturation for sustained duration. Lower is better.
- What steps to take for mitigation: Increase number of max instances: https://cloud.google.com/run/docs/configuring/max-instances.
Runway Container Memory Utilization
- Metric: Runway Container Memory Utilization
- Locations:
- What changes to this metric should prompt a rollback: 80% saturation for sustained duration. Lower is better.
- What steps to take for mitigation: Configure memory limits: https://cloud.google.com/run/docs/configuring/services/memory-limits.
Runway Max Concurrent Requests Utilization
- Metric: Runway Max Concurrent Requests Utilization
- Locations:
- What changes to this metric should prompt a rollback: Worth keeping an eye on this; but may not actually require rollback. 80% saturation for sustained duration. Lower is better.
- What steps to take for mitigation: Increase number of max concurrent requests per instance: https://cloud.google.com/run/docs/configuring/concurrency.
Thanos Remote Write Errors
- Metric: Thanos Remote Write Tenant Errors
- Locations:
- What changes to this metric should prompt a rollback: Elevated Thanos errors for tenant
runway_production
for sustained duration. Lower is better.
Runway Ingress Errors
- Metric: Runway Ingress Errors
- Locations:
- What changes to this metric should prompt a rollback: Elevated error rate for sustained duration. Lower is better.
Runway Ingress Apdex Latency
- Metric: Runway Ingress Apdex Latency
- Locations:
- What changes to this metric should prompt a rollback: Elevated apdex latency for sustained duration. Lower is better.
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.
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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.