2023-07-TBD: [DRAFT] [GPRD] - Delete unused Patroni CI v14 cluster VMs

Production Change

Change Summary

Delete unused Patroni CI v14 cluster VMs.

We have provisioned a Patroni CI v14 cluster (#15982 (closed)) for PG14 upgrade testing - #15993 (closed).

Sometime next week we are planning to rebuild the Patroni CI v14 cluster again from a fresh GPRD CI Patroni v12 cluster disk snapshot for the PG14 upgrade testing.

Since these Patroni cluster nodes are not used at the moment, we would like to delete the Patroni CI v14 cluster VMs.

Related to: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/16461

Change Details

  1. Services Impacted - ServicePatroniCI
  2. Change Technician - @bshah11 @anganga
  3. Change Reviewer - @cmcfarland
  4. Time tracking - 90 minutes
  5. Downtime Component - none

Detailed steps for the change

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 25 minutes

  • Set label changein-progress /label ~change::in-progress

  • Confirm the silences created for patroni-ci-v14 cluster are not expired

  • Execute knife search 'roles:gprd-base-db-patroni-ci-v14' -i

      4 items found

  patroni-ci-v14-102-db-gprd.c.gitlab-production.internal
  patroni-ci-v14-101-db-gprd.c.gitlab-production.internal
  patroni-ci-v14-104-db-gprd.c.gitlab-production.internal
  patroni-ci-v14-103-db-gprd.c.gitlab-production.internal

  • Execute ssh patroni-ci-v14-101-db-gprd.c.gitlab-production.internal "sudo gitlab-patronictl list" and confirm that the patroni cluster name is gprd-patroni-ci-v14 without any patroni cluster nodes listed in the output

       +--------+------+------+-------+----+-----------+
   | Member | Host | Role | State | TL | Lag in MB |
   + Cluster: gprd-patroni-ci-v14 (6959847276950353+
   +--------+------+------+-------+----+-----------+
   Maintenance mode: on

  • Remove Draft from the MR. Rebase the MR and confirm the Terraform plan job show the following output to remove patroni-ci-v14 cluster VMs only. Do not proceed further with the Change if the output does not match the expeted output.

       Plan: 0 to add, 3 to change, 17 to destroy.

  • Remove the chef nodes & clients from Chef, if not removed already

    • knife node delete --yes patroni-ci-v14-10{1..4}-db-gprd.c.gitlab-production.internal
    • knife client delete --yes patroni-ci-v14-10{1..4}-db-gprd.c.gitlab-production.internal

  • Verify the host VMs are deleted. Execute knife search 'roles:gprd-base-db-patroni-ci-v14' -i

      0 items found

  • Set label changecomplete /label ~change::complete

Rollback

There is no rollback needed. If this run fails we iterate on the process and retry.

Rollback steps - steps to be taken in the event of a need to rollback this change

Estimated Time to Complete (mins)

Monitoring

Key metrics to observe

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