Network Load Balancer
Definition
AWS's ultra-high performance Layer 4 load balancer that handles millions of requests per second with ultra-low latency and high availability.
Use Cases
- Epic Games: Handle large volumes of concurrent TCP/UDP player connections for online gameplay services with low latency. — Deployed scalable game backend services on AWS and used Layer 4 load balancing patterns to distribute inbound connections across healthy instances, relying on health checks and horizontal scaling to absorb traffic spikes. (Improved ability to handle sudden surges in player traffic while maintaining responsive connections and reducing the risk of single-server overload.)
- Netflix: Distribute high-volume network traffic to edge and backend services with strong availability characteristics. — Uses AWS extensively and applies load balancing architectures (including Layer 4 where appropriate) to spread traffic across multiple targets and Availability Zones, combined with automation and monitoring for resilience. (Higher service availability and better fault tolerance during infrastructure changes or failures, supporting consistent streaming experiences at scale.)
Provider Equivalents
- AWS: Network Load Balancer (NLB)
- Azure: Azure Load Balancer (Standard)
- GCP: Cloud Load Balancing (TCP/UDP Network Load Balancer)
- OCI: OCI Network Load Balancer
Frequently Asked Questions
- What's the difference between Network Load Balancer and Application Load Balancer?
- Network Load Balancer (NLB) works at Layer 4 (TCP/UDP). It routes traffic based on IP address and port and is optimized for very high throughput and ultra-low latency. Application Load Balancer (ALB) works at Layer 7 (HTTP/HTTPS). It can route based on URL paths, hostnames, headers, and supports features like HTTP redirects and WebSocket at the application layer. Use NLB for raw TCP/UDP performance and ALB for HTTP-aware routing and features.
- When should I use Network Load Balancer?
- Use an NLB when you need to load balance non-HTTP traffic (TCP/UDP), require very low latency, or expect extremely high connection rates/throughput. Common examples include gaming backends, VoIP/SIP, MQTT brokers, custom TCP protocols, and TLS pass-through scenarios where you want to keep encryption end-to-end to your targets.
- How much does Network Load Balancer cost?
- Pricing is usage-based and typically includes a per-hour charge for the load balancer plus charges based on capacity/traffic processed (for AWS, this is commonly measured using Load Balancer Capacity Units, or LCUs). Your cost depends on factors like new connections per second, active connections, bytes processed, and rule/processing needs. Data transfer charges may also apply depending on traffic direction and where targets are located.
Category: networking
Difficulty: advanced
Related Terms
See Also