Postmortem: ElastiCache Routing Misconfiguration & Multi-Region Outage
Date: September 2, 2026
Incident Duration: ~6 hours 30 minutes
Impact: Partial service degradation across EU and US-West regions due to primary cache inaccessibility.
Executive Summary
On September 2, 2026, a scheduled ElastiCache service upgrade triggered a failover of Pangolin’s primary cache node to a replica located within a newly provisioned VPC subnet. A routing table misconfiguration prevented...