Investigation Results: Q2 Server Outage Incident

Timeline of Events

  • 2025-06-09 14:30 UTC

    Initial alert triggered for high CPU usage on `db-prod-1`. [server-logs.txt, line 1024]

  • 2025-06-09 14:38 UTC

    On-call engineer (Alice) acknowledges the alert. Begins investigation. [on-call-alerts.csv, row 56]

  • 2025-06-09 14:55 UTC

    Deployment of new feature `alpha-sort-v2` completed on main application servers. [deploy-logs.txt, line 88]

  • 2025-06-09 15:10 UTC

    Multiple cascading failures reported across all application servers. Site becomes unresponsive. [server-logs.txt, line 3512]

  • 2025-06-09 15:25 UTC

    Decision made to roll back the `alpha-sort-v2` deployment. [dev-chat.log, line 210]

  • 2025-06-09 15:40 UTC

    Systems stabilize and come back online after rollback is complete. [server-logs.txt, line 8092]

Fishbone Diagram (Ishikawa)

  • On-call engineer was new [dev-chat.log, line 15]
  • Team lead on PTO [hr-records.csv, row 112]
  • No load testing in staging [deploy-logs.txt, line 45]
  • Database at 90% capacity [server-logs.txt, line 998]
  • Inefficient DB query in new code [code-review.log, line 554]
  • Outdated server firmware
  • Insufficient memory allocation
  • Monitoring thresholds not updated
  • Latency alerts misconfigured
  • Staging env not identical to prod [dev-chat.log, line 301]
Personnel
Methods
Machines
Materials
Measurements
Environment
Q2 Server Outage