[GSTG] Re-create the database CI cluster

Staging Change

Change Summary

This change is needed to recreate the Pgbouncer CI and Patroni CI clusters using Ubuntu 16.04.

Related issue: Infrastructure#14917

Change Details

  1. Services Impacted - ServicePatroni Database
  2. Change Technician - @nhoppe1
  3. Change Reviewers - @Finotto, @mchacon3
  4. Time tracking - 145 minutes
  5. Downtime Component - N/A

Detailed steps for the change

Pre-Change Steps - steps to be completed before execution of the change

Estimated Time to Complete (mins) - 5 minutes

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 80 minutes

  • Merge the MR config-mgmt!3277
  • Merge the MR config-mgmt!3292
  • Merge the MR config-mgmt!3317
  • Merge the MR chef-repo!1170
  • Execute a git pull of the config-mgmt repository to update the local copy
  • Remove the existing clusters by manually executing in the (updated) config-mgmt repository: cd environments/gstg/ && tf destroy -target="module.patroni-ci" -target="module.pgbouncer-ci" -target="module.postgres-ci-dr-archive" -target="module.postgres-ci-dr-delayed" -target="module.patroni-zfs-ci"
  • Ensure the hosts from the Pgbouncer CI cluster were deregistered from Chef: knife node list | grep gstg | grep pgbouncer-ci
  • Ensure the hosts from the Patroni CI cluster were deregistered from Chef: knife node list | grep gstg | grep patroni-ci
  • Ensure the hosts from the Patroni ZFS CI cluster were deregistered from Chef: knife node list | grep gstg | grep patroni-zfs-ci
  • Ensure the hosts from the Postgres CI DR Archive cluster were deregistered from Chef: knife node list | grep gstg | grep postgres-ci-dr-archive
  • Ensure the hosts from the Postgres CI DR Delayed cluster were deregistered from Chef: knife node list | grep gstg | grep postgres-ci-dr-delayed
  • Re-create the clusters by manually executing in the (updated) config-mgmt repository: cd environments/gstg/ && tf apply -target="module.patroni-ci" -target="module.pgbouncer-ci" -target="module.postgres-ci-dr-archive" -target="module.postgres-ci-dr-delayed" -target="module.patroni-zfs-ci"

Post-Change Steps - steps to take to verify the change

Estimated Time to Complete (mins) - 60 minutes

  • Confirm Consul service exists: consul catalog services | grep patroni-ci
  • Confirm the new hosts are part of the Consul service: consul catalog nodes | grep patroni-ci
  • Connect to any of the replaced Patroni CI hosts and verify they are part of the cluster with the command gitlab-patronictl list
  • Connect to Postgresql and list the database sizes: gitlab-psql -c "\l+"
  • Confirm the Patroni ZFS CI cluster is replicating data: gitlab-psql -c "\l+"
  • Confirm the Postgres CI DR Archive cluster is working and there's low replication lag: gitlab-psql -c "\l+"
  • Confirm the Postgres CI DR Delayed cluster is working and there's low replication lag: gitlab-psql -c "\l+"
  • Confirm the node console-01-sv-gstg.c.gitlab-staging-1.internal can connect to the new Patroni CI hosts by following the console access and granting rails or db access runbooks
  • Confirm the node console-ro-01-sv-gstg.c.gitlab-staging-1.internal can connect to the new Patroni CI hosts by following the console access and granting rails or db access runbooks
  • Verify the backup is working and present in the Google Storage (GS)
  • Verify the disk snapshots for the Patroni CI cluster are being done.
  • Review connectivity to the Patroni CI cluster through the Pgbouncer CI and the Pgbouncer CI Sidekiq clusters
  • Verify monitoring

Rollback

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

Estimated Time to Complete (mins) - N/A

  • No rollback is available/possible for this change.

Monitoring

Key metrics to observe

Summary of infrastructure changes

  • Does this change introduce new compute instances?
  • Does this change re-size any existing compute instances?
  • Does this change introduce any additional usage of tooling like Elastic Search, CDNs, Cloudflare, etc?

Change Reviewer checklist

C4 C3 C2 C1:

  • 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:

  • 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.

Change Technician checklist

  • This issue has a criticality label (e.g. C1, C2, C3, C4) and a change-type label (e.g. changeunscheduled, changescheduled) based on the Change Management Criticalities.
  • This issue has the change technician as the assignee.
  • Pre-Change, Change, Post-Change, and Rollback steps and have been filled out and reviewed.
  • This Change Issue is linked to the appropriate Issue and/or Epic
  • Necessary approvals have been completed based on the Change Management Workflow.
  • 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.
  • 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.)
  • 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.
Edited by Nels Nelson