RB-104: Authentication Service Latency Triage Runbook
Date: 2025-09-27 Service: Authentication Service Affected Services: Authentication Service, Checkout Service, Billing Service, Inventory Service, Notification Service Incident References: INC-2025-104, INC-2025-105 Primary Dashboard: acme/authentication/latency-triage
When To Use
Use this runbook when Authentication Service shows symptoms related to latency triage, including SLO burn, elevated p95 latency, queue backlog, dependency saturation, or customer-visible failures. This procedure is informed by incidents INC-2025-104, INC-2025-105.
Preconditions
- Confirm the incident commander and service owner are assigned.
- Confirm recent deployments and feature flags for Authentication Service.
- Review API health for API-AUTHENTICATION-01, API-AUTHENTICATION-02, API-AUTHENTICATION-03, API-AUTHENTICATION-04.
- Check whether Checkout Service or Billing Service is seeing downstream impact.
Procedure
- Capture current error rate, latency, saturation, and queue depth.
- Compare current behavior with the baseline dashboard for Authentication Service.
- If retries are amplifying traffic, reduce client retry budgets and enable degraded mode.
- If data repair is required, run a dry-run replay before any write operation.
- Communicate status in Slack and link the active Jira ticket.
Validation
Recovery is complete when customer-facing error rate returns to baseline, API API-AUTHENTICATION-01 is healthy, and dependent services report no continuing impact.