Overview:
An essential part of contemporary cloud architecture, a load balancer assists in dividing up incoming network traffic among several servers (instances). This improves your application’s availability, scalability, and fault tolerance by preventing any one server from carrying an excessive amount of load. The Elastic Load Balancing (ELB) service in AWS facilitates load balancing by supporting a variety of load balancer types that are tailored to different requirements.
Following Steps:
1. Recognize the Function of Load Balancers
To distribute incoming network traffic among several servers or instances, load balancers are necessary. This guarantees improved performance, fault tolerance, and high availability by preventing any one server from acting as a bottleneck.
2. Pick the Right Type of Load Balancer
With its Elastic Load Balancing (ELB) service, AWS provides three different kinds of load balancers:
Application Load Balancer (ALB): Provides sophisticated routing (Layer 7) and is optimal for HTTP/HTTPS traffic.
Network Load Balancer (NLB): Provides ultra-low latency and high throughput (Layer 4), making it ideal for TCP/UDP traffic.
Firewalls and other third-party virtual appliances are deployed via a gateway load balancer (GLB) (Layer 3).
Because of its adaptability and compatibility with contemporary web frameworks, ALB is recommended for the majority of web applications.
3. Establish an AWS load balancer
Navigate to the AWS Management Console’s EC2 Dashboard.
Click “Create Load Balancer” after selecting “Load Balancers.”
- Select the type of load balancer, such as ALB.
- Set up the name and scheme (internal or internet-facing).
- Protocol and port listeners.
- Subnets and availability zones for multi-AZ setup.
- To regulate incoming and outgoing traffic, use security groups.
- Secure HTTPS communication is made possible by SSL/TLS certificates.
4. Establish and Set Up Target Groups
Establish target groups that consist of Lambda functions, IP addresses, or EC2 instances.
Indicate the target type, protocol, and port.
Set up health checks to keep an eye on instance availability, such as an HTTP ping to /health.
Set up EC2 instances for the intended audience.
5. Set up routing rules and listeners
Configure listeners to keep an eye on particular ports, such as 80 for HTTP and 443 for HTTPS.
Establish routing rules, such as path-based (e.g., /images → Image target group) and host-based (e.g., api.example.com → API target group). Use AWS Certificate Manager (ACM) to link an SSL certificate to HTTPS. If necessary, set up OIDC authentication, fixed replies, or redirects.
6. Check the load balancing system.
To reach the load balancer via a browser, use the DNS name that AWS has provided.
Verify that requests are sent to backend instances correctly.
To verify failover behavior and make sure traffic is diverted to healthy instances, stop an instance.
For further testing, use programs like curl, Postman, or browser development tools.