Understanding the Differences Between Application Load Balancer and Network Load Balancer

Load balancers are essential components for distributing incoming network traffic across multiple servers to ensure high availability and reliability. AWS provides two prominent types of load balancers: Application Load Balancer (ALB) and Network Load Balancer (NLB). Although both serve the purpose of balancing loads, they have distinct characteristics suited for different scenarios.

Application Load balancer VS Network Load balancer

Application Load Balancer (ALB):

ALBs operate at the application layer (Layer 7) of the OSI model, making intelligent routing decisions based on the content of the request. They are well-suited for applications that require advanced routing techniques and support for features such as content-based routing, host-based routing, and path-based routing. ALBs are capable of routing HTTP and HTTPS traffic and are often used for modern web applications and microservices architectures. They also support features like cookie-based sessions and WebSocket protocols.

Use Cases for ALB:

1. Web Applications: ALBs are ideal for web applications that require routing based on URL paths or hostnames.
2. Microservices Architectures: With support for containerized applications and dynamic ports, ALBs efficiently handle routing traffic to various microservices.
3. Websites with Secure Traffic: ALBs offer SSL/TLS termination, enabling the secure transfer of data between clients and servers.

Network Load Balancer (NLB):

NLBs function at the transport layer (Layer 4) of the OSI model and are capable of handling TCP, UDP, and TLS traffic. They are designed to manage high-throughput traffic and are particularly effective for use cases that require ultra-low latency. NLBs are known for their ability to handle millions of requests per second while maintaining high performance and low latency. They are often used for applications that demand static IP addresses or require handling of volatile traffic patterns.

Use Cases for NLB:

1. High-Performance Computing (HPC): NLBs are suitable for HPC applications that require low latency and high throughput.
2. IoT Applications: With the capability to handle millions of requests simultaneously, NLBs are ideal for managing the traffic generated by IoT devices.
3. Applications Requiring Static IP Addresses: NLBs provide a static IP that remains constant even when the underlying infrastructure changes, making them suitable for applications with strict IP-based requirements.

To dive deeper into the details and see the working of application load balancing and network load balancing you can clone my github repository and follow the guide.