2023-08-17: Update ApplicationSetting with wal_rate settings for 'gprd'

Production Change

Change Summary

gitlab-org/gitlab!128365 (merged) introduced WAL rate indicator in database health check framework, we store wal_rate configs in ApplicationSetting.prometheus_alert_db_indicators_settings. This CR aims to add those configuration for gprd.

Notes:

• #16138 (closed) updates the same for gstg.
• The functionality is behind db_health_check_wal_rate FF (will be enabled after this CR changes goes in).
• gitlab-org/gitlab#407158 (closed) is opened to make this configuration to be in sync with any future changes on PromQL.

Commands to be run in the console

application_setting = ApplicationSetting.last
prometheus_alert_db_indicators_settings = application_setting.prometheus_alert_db_indicators_settings

application_setting.update(prometheus_alert_db_indicators_settings: prometheus_alert_db_indicators_settings.merge(
  wal_rate_sli_query: {
    main: "avg(postgres:pg_xlog_bytes_per_second:rate5m{env='gprd', type='patroni'})",
    ci: "avg(postgres:pg_xlog_bytes_per_second:rate5m{env='gprd', type='patroni-ci'})"
  },
  wal_rate_slo: {
    main: 70000000,
    ci: 70000000
  }
))

Rollback commands

old_config = {
  "prometheus_api_url" => "http://thanos-query-frontend-internal.ops.gke.gitlab.net:9090",
  "apdex_slo" => {
    "ci" => 0.997,
    "main" => 0.997
  },
  "apdex_sli_query" => {
    "ci" => "avg_over_time(gitlab_service_apdex:ratio_5m{env='gprd',environment='gprd',monitor='global',type='patroni-ci'}[5m])",
    "main" => "avg_over_time(gitlab_service_apdex:ratio_5m{env='gprd',environment='gprd',monitor='global',type='patroni'}[5m])"
  }
}

application_setting = ApplicationSetting.last

application_setting.update(prometheus_alert_db_indicators_settings: old_config)

Change Details

1. Services Impacted - Thanos Query FE, Batched background migrations
2. Change Technician - @praba.m7n
3. Change Reviewer -
4. Time tracking - unknown
5. Downtime Component - none

Detailed steps for the change

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - Single update call to Db, should be quick

• Set label changein-progress /label ~change::in-progress
• Run above commands in the rails console in gprd ENV
• Set label changecomplete /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) - Single update call to Db, should be quick

• Run the rollback commands in gprd rails console.
• Set label changeaborted /label ~change::aborted

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 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.