[GPRD] [2023-06-24 14:00 UTC -19:00 UTC] - Upgrade PostgreSQL to PG14 on CI cluster

Production Change

Change Summary

The Patroni CI cluster currently runs on Postgres 12, an outdated Postgres engine. During the maintenance, we will upgrade a new standby cluster to Postgres 14, and update the Consul service registration to point Gitlab.com applications to the corresponding new Patroni cluster running PG 14.

As defined in &802 (closed) and https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/16443 this will roll-out the PostgreSQL 14 upgrade on [GPRD] CI cluster.

Key Benefits:

  • Up-to-date Postgresqsl engine will provide increased security and stability.
  • Performance improvements in Postgres 14 will significantly impact our ability to operate the primary database at our current scale

Downtime Requirements:

The PG 14 upgrade process will be an online process with near zero downtime that should take up to a maximum of 5 mins. However, in the unlikely event that we need to rollback, it will require downtime

Postgres Upgrade Rollout Team

Role Assigned To
🐺 Coordinator @rhenchen.gitlab
🔪 Playbook-Runner @bshah11
☎ Comms-Handler @kwanyangu
🐘 DBRE @alexander-sosna
🐬 SRE @anganga
🏆 Quality @niskhakova @treagitlab
🎩 IMOC @kwanyangu
📣 CMOC @faleksic @asmaa.hassan, @onemoz, @rkelly
🚑 EOC @knottos, @stejacks-gitlab
💾 Head Honcho ADD_ON_DEMAND

Change Details

  1. Services Impacted - ServicePatroni ServicePatroniCI ServiceAPI ServiceCI Runners ServiceWeb ServicePostgres Database
  2. Change Technician - @bshah11 @alexander-sosna
  3. Change Reviewer - @NikolayS @vitabaks @rhenchen.gitlab
  4. Time tracking - 5 hours
  5. Downtime Component - Small, will be evaluated.

Detailed steps for the change

We will pretend that GitLab.com would be unavailable during the execution of the CR and we'll use ops.gitlab.net for the detailed instructions. We will use the following issue for the Patroni CI cluster:

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 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 (If needed! Cases include DB change) prior to 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.
Edited by Biren Shah