Draft: [GSTG] PgBouncer upgrade

Production Change

Change Summary

We are upgrading PgBouncer to the current stable version and set optimized defaults for internal settings as well as certain OS tuning parameters.

On [db-benchmarking] we will enable all settings globally, restart the services and test the effect. On all other stages we will

  1. Enable the new settings for Registry
  2. Restart PgBouncer service gracefully
  3. Observe the effects
  4. Enable it globally
  5. Restart PgBouncer service gracefully on CI
  6. Observe
  7. Restart PgBouncer service gracefully on Main
  8. Observe

Change Details

  1. Services Impacted - ServicePatroniRegistry ServicePatroni ServiceAPI ServiceContainer Registry ServiceWeb ServicePostgres Database
  2. Change Technician - @alexander-sosna
  3. Change Reviewer - DRI for the review of this change
  4. Time tracking - Time, in minutes, needed to execute all change steps, including rollback
  5. Downtime Component - No Downtime!

Detailed steps for the change

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - Estimated Time to Complete in Minutes

  • Set label changein-progress /label ~change::in-progress
  • Merge Upgrade and tune pgBouncer on GSTG registry
  • Use https://gitlab.com/gitlab-com/gl-infra/ansible-migrations to restart all bouncer services for registry. TODO
  • Check all is as expected
    • Check sysctl values where changed on one host 
      sysctl -a | grep port_range
net.ipv4.ip_local_port_range = 10000	65535
    • Check service is running correct version on one host 
      pgb-console
...
pgbouncer=# SHOW VERSION;
 version
------------------
PgBouncer 1.19.0
(1 row)
    • Watch metrics for 10 Minute TODO
  • Merge Upgrade and tune pgBouncer on GSTG
  • Use https://gitlab.com/gitlab-com/gl-infra/ansible-migrations to restart all bouncer services for CI. TODO
  • Check all is as expected
    • Check sysctl values where changed on one host 
      sysctl -a | grep port_range
net.ipv4.ip_local_port_range = 10000	65535
    • Check service is running correct version on one host 
      pgb-console
...
pgbouncer=# SHOW VERSION;
 version
------------------
PgBouncer 1.19.0
(1 row)
    • Watch metrics for 10 Minute TODO
  • Use https://gitlab.com/gitlab-com/gl-infra/ansible-migrations to restart all bouncer services for Main. TODO
  • Check all is as expected
    • Check sysctl values where changed on one host 
      sysctl -a | grep port_range
net.ipv4.ip_local_port_range = 10000	65535
    • Check service is running correct version on one host 
      pgb-console
...
pgbouncer=# SHOW VERSION;
 version
------------------
PgBouncer 1.19.0
(1 row)
  • Set label changecomplete /label ~change::complete

Rollback

We do not plan for a rollback, we will fix forward the procedure for GSTG.

Monitoring

Key metrics to observe

  • Metric: Metric Name
    • Location: Dashboard URL
    • What changes to this metric should prompt a rollback: Describe Changes

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 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.
Edited by Alexander Sosna