# Production Change ## Change Summary This change re-directs canary traffic to directly reach the API backends in Kubernetes without going through the NGINX controller from HAProxy. Main production API traffic is unaffected by this CR and will be migrated in a follow-up CR after the canary rollout has been observed in production. This is the first step in deprecating and removing NGINX in Production environment , read more [here](https://gitlab.com/gitlab-com/gl-infra/production-engineering/-/work_items/28303) ## Change Details 1. **Services Impacted** - ~"Service::API" ~"Service::NGINX" 2. **Change Technician** - @thisisshreya @haseeb_ahmed 3. **Change Reviewer** - @pguinoiseau 4. **Scheduled Date and Time (UTC in format YYYY-MM-DD HH:MM)** - 2026-05-06 12:30 5. **Time tracking** - 180 minutes 6. **Downtime Component** - none > [!important] > > If your change involves scheduled maintenance, add a step to set and [unset maintenance mode](https://gitlab.com/gitlab-com/runbooks/-/blob/master/docs/monitoring/set_maintenance_window.md) per our runbooks. This will make sure SLA calculations adjust for the maintenance period. > [!warning] > > **Server state persistence window:** During this change, HAProxy server state persistence will be temporarily disabled. While persistence is disabled, any HAProxy reload/restart will reset MAINT/DRAIN state — meaning a drained canary backend will become undrained. This will be communicated to release managers as part of this C1 CR, and **the window between disabling and re-enabling persistence must be kept as short as possible**. See [context](https://gitlab.com/gitlab-com/gl-infra/production-engineering/-/work_items/28303#note_3128214144). > [!note] > > This CR only moves `canary_api` traffic off NGINX. The main `api` backend stays on the NGINX path and will be migrated in a separate follow-up CR. ## Preparation > [!note] > > The following checklists must be done in advance, before setting the label ~"change::scheduled" ### Change Reviewer checklist ~C4 ~C3 ~C2 ~C1: - [x] Check if the following applies: - The **scheduled day and time** of execution of the change is appropriate. - The [change plan](#detailed-steps-for-the-change) is technically accurate. - The change plan includes **estimated timing values** based on previous testing. - The change plan includes a viable [rollback plan](#rollback). - The specified [metrics/monitoring dashboards](#key-metrics-to-observe) provide sufficient visibility for the change. ~C2 ~C1: - [x] 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 - [x] The [Change Criticality](https://handbook.gitlab.com/handbook/engineering/infrastructure-platforms/change-management/#change-criticalities) has been set appropriately and requirements have been reviewed. - [x] The [change plan](#detailed-steps-for-the-change) is technically accurate. - [x] The [rollback plan](#rollback) is technically accurate and detailed enough to be executed by anyone with access. - [x] This Change Issue is linked to the appropriate Issue and/or Epic - [x] Change has been tested in staging and results noted in a comment on this issue. - [x] A dry-run has been conducted and results noted in a comment on this issue. - [x] The change execution window respects the [Production Change Lock periods](https://about.gitlab.com/handbook/engineering/infrastructure/change-management/#production-change-lock-pcl). - [x] Once all boxes above are checked, mark the change request as scheduled: `/label ~"change::scheduled"` - [x] For ~C1 and ~C2 change issues, the change event is added to the [GitLab Production](https://calendar.google.com/calendar/embed?src=gitlab.com_si2ach70eb1j65cnu040m3alq0%40group.calendar.google.com) calendar by the [change-scheduler bot](https://gitlab.com/gitlab-com/gl-infra/ops-team/toolkit/change-scheduler). It is schedule to run every 2 hours. - [x] For ~C1 and ~C2 change issues, Platform Leadership provides approval with the ~platform_leadership_approved label on the issue. Mention `@gitlab-org/saas-platforms/change-review-leadership` in this issue with a reference to [review guidelines](https://handbook.gitlab.com/handbook/engineering/infrastructure-platforms/change-management/platform-leadership-review/) to get approval and provide visibility to all infrastructure managers. - [x] For ~C1, ~C2, or ~"blocks deployments" change issues, confirm with Release managers that the change does not overlap or hinder any release process (In `#production` channel, mention `@release-managers` and this issue and await their acknowledgment.) - [ ] For ~C1 change issues or ~C2 change issues happening during weekend, SREs on-call must be informed [at least 2 weeks in advance](https://handbook.gitlab.com/handbook/engineering/infrastructure-platforms/change-management/#approval). Check [the incident.io GitLab.com Production EOC schedule](https://app.incident.io/gitlab/on-call/schedules/01K5YWAGZ7YCQGAG7ATQ9XQWHW) to find who will be on-call at the scheduled day and time. ## Detailed steps for the change ### Pre-execution steps - [x] Prepare and merge [MR](https://gitlab.com/gitlab-cookbooks/gitlab-haproxy/-/merge_requests/457) in [`gitlab-haproxy`](https://gitlab.com/gitlab-cookbooks/gitlab-haproxy) to extend the retry/timeout parity config to `canary_api` only (across all environments including production). Once merged, the cookbook version bump MR in [`chef-repo`](https://gitlab.com/gitlab-com/gl-infra/chef-repo) is auto-generated - do not merge that chef-repo MR until Phase 2 of the CR. - [x] Prepare [MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7216) to disable server persistence in production for the main flavour of HAProxy - [x] Prepare [canary MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7254) to update the `canary_api` backend IP and healthcheck - [x] Create PAT for gitlab.com with api access > [!note] > > The following steps should be done right at the scheduled time of the change request. The [preparation steps](#preparation) are listed above. - [x] Make sure all tasks in [Change Technician checklist](#change-technician-checklist) are done - [x] For ~C1 and ~C2 change issues, the SRE on-call has been informed prior to change being rolled out. - [x] The SRE on-call provided approval with the ~eoc_approved label on the issue. - [x] For ~C1, ~C2, or ~"blocks deployments" change issues, Release managers have been informed prior to change being rolled out. (In `#production` channel, mention `@release-managers` and this issue and await their acknowledgment.) **Explicitly call out the persistence-disabled window and MAINT/DRAIN reset risk.** - [x] There are currently no [active incidents](https://gitlab.com/gitlab-com/gl-infra/production/-/issues/?sort=created_date&state=opened&label_name%5B%5D=Incident%3A%3AActive&or%5Blabel_name%5D%5B%5D=severity%3A%3A1&or%5Blabel_name%5D%5B%5D=severity%3A%3A2&first_page_size=20) that are ~severity::1 or ~severity::2 - [ ] 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. ### Change steps - steps to take to execute the change _Estimated Time to Complete (mins)_ - 180 mins > [!note] > > GPRD has \~60 `haproxy-main*` nodes. Cinc server's default max concurrency is 10; we bump to `-C 20` for steps we are confident in, and use a single test node (`haproxy-main-01-lb-gprd`) to validate the rollout before proceeding. #### Phase 1 — Disable server state persistence - [x] Set label ~"change::in-progress" `/label ~change::in-progress` - [x] Merge [MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7216) to disable server state persistence for HAProxy main nodes - [x] **Test node:** Run chef-client on a single node first to validate the change ``` knife ssh 'name:haproxy-main-01-lb-gprd.c.gitlab-production.internal AND chef_environment:gprd' 'sudo chef-client' ``` - [x] Validate server state persistence is disabled on the test node ``` knife ssh 'name:haproxy-main-01-lb-gprd.c.gitlab-production.internal AND chef_environment:gprd' \ "sudo grep -E 'server-state-file|load-server-state-from-file' /etc/haproxy/haproxy.cfg | wc -l | awk '\$1==2{print \"yes, present\"} \$1!=2{print \"no, not present\"}'" ``` **We want the test node to respond with "no, not present"** - [x] **Rollout:** Once the test node is validated, roll out to the remaining nodes concurrently (`-C 20`) ``` knife ssh -C 20 'name:haproxy-main* AND chef_environment:gprd' 'sudo chef-client' ``` - [x] Validate server state persistence is disabled across the whole fleet ``` knife ssh 'name:haproxy-main* AND chef_environment:gprd' \ "sudo grep -E 'server-state-file|load-server-state-from-file' /etc/haproxy/haproxy.cfg | wc -l | awk '\$1==2{print \"yes, present\"} \$1!=2{print \"no, not present\"}'" ``` **We want all the nodes to respond with "no, not present"** #### Phase 2 — Switch canary_api backend IPs (route traffic away from NGINX) > [!warning] > > Persistence is now disabled. Minimise the time spent in Phase 2. Any HAProxy reload here will reset MAINT/DRAIN state on all nodes. - [x] Disable chef-client on the HAProxy main nodes ``` knife ssh 'name:haproxy-main* AND chef_environment:gprd' 'sudo /usr/local/bin/chef-client-disable "Re-routing traffic away from NGINX https://gitlab.com/gitlab-com/gl-infra/production/-/work_items/21809 "' ``` - [x] Merge the [auto-generated chef-repo MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7270) that bumps the gitlab-haproxy cookbook version (adds retry/timeout config for `canary_api`) - [x] Merge [canary MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7254) updating the `canary_api` backend IP and healthcheck (canary traffic will start going directly to the `gitlab-webservice-api` LoadBalancer, bypassing NGINX) - [x] Enable chef-client on the test node ``` knife ssh 'name:haproxy-main-01-lb-gprd.c.gitlab-production.internal' 'sudo /usr/local/bin/chef-client-enable' ``` - [x] Run chef-client manually on the test node, and only if chef-client succeeds reload HAProxy ``` knife ssh 'name:haproxy-main-01-lb-gprd.c.gitlab-production.internal' 'sudo chef-client && sudo systemctl reload haproxy' ``` - [x] SSH into the test HAProxy VM and test connectivity to the canary API backend using the canary cookie. Using `--connect-to` ensures the request goes through this specific test node's HAProxy (via the internal port `11443`) rather than being load-balanced across the fleet by the GLB. ``` ssh haproxy-main-01-lb-gprd.c.gitlab-production.internal ``` ###### On the node: ``` curl -vL \ -H "PRIVATE-TOKEN: ${PAT}" \ -b "gitlab_canary=true" \ --connect-to gitlab.com:443:127.0.0.1:11443 \ "https://gitlab.com/api/v4/user" ``` - [x] Enable chef-client and roll out the canary backend IP change to the remaining HAProxy main nodes concurrently (`-C 20`) ``` knife ssh -C 20 'name:haproxy-main* AND chef_environment:gprd' 'sudo /usr/local/bin/chef-client-enable && sudo chef-client && sudo systemctl reload haproxy' ``` - [ ] Check `canary_api` backend health and error rates in [Grafana](https://dashboards.gitlab.net/d/haproxy/haproxy?from=now-3h&orgId=1&refresh=5m&timezone=utc&to=now&var-backend=canary_api&var-code=$__all&var-datasource=mimir-gitlab-gprd&var-env=gprd&var-frontend=$__all&var-host=$__all&var-interval=$__auto&var-port=&var-server=$__all&viewPanel=panel-27) - [ ] Confirm canary NGINX traffic in GPRD is zero in [Grafana](https://dashboards.gitlab.net/d/nginx-main/nginx3a-overview?orgId=1&from=now-3h&to=now&timezone=utc&var-PROMETHEUS_DS=mimir-gitlab-gprd&var-environment=gprd&var-stage=cny&viewPanel=panel-2597844128) - main `api` traffic should remain on NGINX (this is expected and will be migrated in the follow-up CR) #### Phase 3 - Re-enable server state persistence - [x] Revert [MR](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7285) to re-enable server state persistence - [x] Run chef-client concurrently to roll out the re-enable across all nodes ``` knife ssh -C 20 'name:haproxy-main* AND chef_environment:gprd' 'sudo chef-client' ``` - [ ] Confirm persistence is re-enabled on all nodes ``` knife ssh 'name:haproxy-main* AND chef_environment:gprd' \ "sudo grep -E 'server-state-file|load-server-state-from-file' /etc/haproxy/haproxy.cfg | wc -l | awk '\$1==2{print \"yes, present\"} \$1!=2{print \"no, not present\"}'" ``` **We want all the nodes to respond with "yes, present"** - [ ] Set label ~"change::complete" `/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 minutes - [x] Ensure server persistence is disabled and chef-client is enabled - [x] Revert the relevant MR(s) (backend IP change and/or cookbook version bump in phase 2): - [x] canary: revert https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7254 (canary backend) - [x] revert the [cookbook version bump MR ](https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/7270)(chef-repo) - [x] Reload HAProxy on the test node and verify `canary-api` service is reachable and backend is healthy - [x] Roll out the revert to the other nodes with `knife ssh -C 20 ...` - [x] Revert MR to re-enable server state persistence and run chef-client with `-C 20` - [x] Set label ~"change::aborted" `/label ~change::aborted` ## Monitoring ### Key metrics to observe - Metric: HAProxy Dashboard - Location: [HAProxy Dashboard](https://dashboards.gitlab.net/d/haproxy/haproxy?from=now-3h&orgId=1&refresh=5m&timezone=utc&to=now&var-backend=canary_api&var-code=$__all&var-datasource=mimir-gitlab-gprd&var-env=gprd&var-frontend=$__all&var-host=$__all&var-interval=$__auto&var-port=&var-server=$__all&viewPanel=panel-27) - What changes to this metric should prompt a rollback: A sudden significant increase in errors or latency on the `canary_api` backend, or unexpected impact to main `api` traffic