Karpenter

Overview

Karpenter is a Kubernetes node autoscaler that provisions right-sized compute resources in response to changing application load. Unlike Cluster Autoscaler which scales predefined node groups, Karpenter provisions nodes based on aggregate pod resource requirements, enabling better bin-packing and cost optimization.

Key Differences from Cluster Autoscaler

• Direct provisioning: Talks directly to cloud provider APIs (no node groups required)
• Fast scaling: Provisions nodes in seconds vs minutes
• Flexible instance selection: Chooses from all available instance types automatically
• Consolidation: Actively replaces nodes with cheaper alternatives
• Spot instance optimization: First-class support with automatic fallback

When to Use Karpenter