What are the 3 Types of Load Balancers in AWS?

Load balancing is a crucial aspect of ensuring high availability, scalability, and fault tolerance in cloud computing environments. Amazon Web Services (AWS) provides several types of load balancers to distribute incoming traffic across multiple targets, such as instances, containers, and IP addresses.

The three main types of load balancers in AWS are

1. the Classic Load Balancer (CLB),
2. the Application Load Balancer (ALB), and
3. the Network Load Balancer (NLB).

1. Classic Load Balancer (CLB)

The Classic Load Balancer is the oldest of the three types and is designed for applications that were built within the EC2-Classic network. It operates at both the application and network layers, distributing traffic across instances based on either application or network-level information.

While it provides basic load balancing capabilities, CLB lacks some of the advanced features available in the newer load balancers.

2. Application Load Balancer (ALB)

The Application Load Balancer is a Layer 7 load balancer that is ideal for routing HTTP/HTTPS traffic. It is highly suited for modern, microservices-based architectures. ALB can route requests based on content, enabling more advanced load-balancing scenarios.

• It supports host-based and path-based routing, allowing for efficient handling of multiple applications running on the same set of instances.
• Additionally, ALB provides features such as SSL termination, WebSocket support, and native support for containerized applications.

3. Network Load Balancer (NLB)

The Network Load Balancer operates at the transport layer (Layer 4) and is designed to handle high-throughput traffic. NLB is well-suited for scenarios where extreme performance and low latency are critical, such as gaming applications or large-scale media streaming.

• It distributes incoming TCP/UDP traffic across a group of targets based on IP protocol data.
• NLB is highly scalable and can handle millions of requests per second, making it suitable for demanding workloads.

Conclusion

Each type of load balancer in AWS has its strengths and is designed to address specific use cases. Users should choose the appropriate load balancer based on factors such as the nature of their applications, performance requirements, and the desired level of control over routing and traffic management. Combining these load balancers with Auto Scaling groups and other AWS services allows users to build resilient and scalable architectures in the cloud.