ARC zonal shift support for EKS Auto Mode and Karpenter

This article announces Zonal Shift support for EKS Auto Mode and Karpenter, enabling automatic recovery from Availability Zone failures.

• Cordons nodes in affected zones and prevents new pod scheduling there
• Deregisters pod endpoints from load balancers to stop traffic routing to impaired zones
• Blocks new capacity provisioning in affected zones and suspends voluntary disruptions
• EKS Auto Mode enables Zonal Shift with a single CLI command; OSS Karpenter requires version 1.12.0+ and IAM policy configuration
• Detects manual and automatic shifts by polling ARC API every 30 seconds
• Best practices include multi-AZ pod distribution, avoiding singleton deployments, configuring pod disruption budgets, and protecting stateful workloads
• AWS Resilience Hub identifies workloads with zonal redundancy gaps using AI-driven failure mode assessments

Zonal Shift provides fast, automated recovery from AZ impairments when combined with proper multi-AZ architecture and AWS Resilience Hub assessments.