Why do I need a Load Balancer?
Understand the 5 main reasons why you always need to have a load balancer in front of your servers and learn about the different types available on AWS.
Published Aug 2, 2024
In today’s digital world, ensuring the seamless performance and availability of your web applications is crucial. One key component that plays a vital role in achieving this is a load balancer. Here are five compelling reasons why you should always put a load balancer in front of your servers.
A load balancer distributes incoming traffic across multiple servers, ensuring no single server becomes a bottleneck. This distribution enhances the overall performance of your application by utilizing resources efficiently. It also increases reliability, as the load balancer can reroute traffic to other servers if one fails, ensuring your application remains available.
As your application grows, you’ll need to handle increasing amounts of traffic. A load balancer makes it easier to add more servers to your infrastructure without downtime. It manages the distribution of traffic to these new servers, allowing your application to scale seamlessly and handle larger loads.
One thing that is less intuitive about load balancers is that they can add an extra layer of security to your infrastructure. They can help protect against Distributed Denial of Service (DDoS) attacks by distributing the malicious traffic across multiple servers. Additionally, load balancers can terminate SSL/TLS, offloading the computationally expensive encryption process from your application servers, and inspect incoming traffic for malicious patterns.
By distributing traffic evenly across multiple servers, a load balancer ensures that all your servers are utilized optimally. This balanced distribution prevents any single server from being overburdened while others remain underutilized, leading to more efficient use of resources and potentially lowering costs.
With a load balancer, you can perform maintenance on your servers without taking your application offline. By directing traffic away from the server being maintained and distributing it to the remaining servers, you ensure continuous availability. Once maintenance is complete, the load balancer can smoothly reintegrate the updated server back into the pool.
Amazon Web Services (AWS) provides several load balancing options to meet different needs:
The Application Load Balancer (ALB) routes HTTP/HTTPS (layer 7) traffic based on advanced application-level information. It supports features like content-based routing, host-based routing, and path-based routing, making it highly versatile for handling complex traffic patterns. ALB is recommended for most use cases involving HTTP/HTTPS traffic due to its ability to understand and route traffic based on content, providing enhanced performance and flexibility for web applications.
The Network Load Balancer (NLB) routes TCP/UDP (layer 4) traffic based on IP addresses and ports. It is designed for scenarios where extreme performance is required, capable of handling millions of requests per second with ultra-low latency and high throughput. NLB is ideal for load balancing TCP or UDP traffic, making it a perfect choice for high-performance, latency-sensitive applications.
The Gateway Load Balancer (GWLB) routes traffic to third-party virtual appliances such as firewalls, intrusion prevention systems (IPS), and intrusion detection systems (IDS). GWLB helps integrate these appliances into your network in a scalable and managed way, allowing you to deploy, scale, and manage third-party virtual appliances seamlessly within your AWS environment. This load balancer is particularly useful for enhancing the security and functionality of your network infrastructure.
The Classic Load Balancer (CLB) routes traffic based on either application-level (layer 7) or network-level (layer 4) information. It supports TCP, SSL, HTTP, and HTTPS protocols, providing flexibility in traffic routing. CLB is recommended for legacy applications or when you need strict control over the load balancing behavior. While newer load balancers like ALB and NLB offer more features and better performance, CLB remains useful for certain legacy scenarios where precise control and compatibility are required.
Understanding the different load balancing options available on AWS helps you choose the right tool for your specific application needs, ensuring optimal performance, scalability, and security for your infrastructure.
By leveraging the power of load balancers, you can ensure that your application remains robust, efficient, and ready to scale as your user base grows.