Using Load Balancer Capacity Unit Reservation to prepare for sharp increases in traffic

AWS has introduced Load Balancer Capacity Unit (LCU) Reservation, a new feature for Application and Network Load Balancers that allows users to proactively scale their load balancers before anticipated traffic spikes.

• Helps prepare for events like product launches, sales, or traffic migrations
• Enables setting a minimum capacity for load balancers in advance
• Works alongside existing ELB dynamic scaling systems
• Supports both ALB and NLB with TCP/UDP listeners
• Can be configured through AWS Management Console or AWS CLI

Key considerations include using the feature for short intervals, considering load balancer sharding for long-term unpredictable traffic, and understanding that reserved capacity is billed at a specific rate. The feature provides more control over load balancer capacity and helps manage sudden traffic increases.