Configuring an Application Load Balancer (ALB) on AWS EC2 for High Availability and Scalability. ☁

AWS EC2 instances provide scalable and reliable computing resources in the cloud, but they are not inherently fault-tolerant or highly available. To address these limitations, you can use an Application Load Balancer (ALB), which distributes incoming traffic to multiple EC2 instances based on defined routing rules. In this tutorial, I'll show you how to configure an ALB on AWS EC2 for high availability and scalability.

Prerequisites

• An AWS account with EC2 access

• One or more EC2 instances running a web server (such as Apache or Nginx)

• An Application Load Balancer

• A registered domain name

Step 1: Create a Target Group

The first step is to create a target group, which is a logical grouping of EC2 instances that you want to receive traffic from the ALB. To create a target group, navigate to the EC2 console, select "Target Groups" from the left-hand menu, and click "Create target group."

Give your target group a name and select the protocol and port that your web server is using. You can also specify health check settings to ensure that the ALB only sends traffic to healthy instances.

Step 2: Create an Application Load Balancer

Once you have created a target group, you can create an ALB that will distribute incoming traffic to the instances in the target group. To create an ALB, navigate to the EC2 console, select "Load Balancers" from the left-hand menu, and click "Create Load Balancer."

Select "Application Load Balancer" and give your load balancer a name. Choose the VPC where your EC2 instances are located, and select the target group that you created in step 1.

Configure the listener settings, which define the port and protocol that the ALB will use to receive traffic. You can also configure routing rules to direct traffic to specific target groups based on the URL path or host header.

Step 3: Configure DNS

To route traffic to your ALB, you need to configure your DNS settings to point your domain name to the ALB's DNS name. You can find the ALB's DNS name in the EC2 console under "Load Balancers."

Update your domain name's DNS settings to create a CNAME record that points to the ALB's DNS name. This will allow traffic to be directed to the ALB, which will distribute it to the instances in your target group.

Step 4: Test the ALB🚀

Once you have configured the ALB and DNS settings, you can test the configuration by accessing your domain name in a web browser. The ALB should distribute incoming traffic to the instances in your target group, providing high availability and scalability for your application.

Conclusion In this blog, I explained how to configure an Application Load Balancer (ALB) on AWS EC2 for high availability and scalability. By following these steps, you can distribute incoming traffic to multiple EC2 instances, providing fault tolerance and ensuring that your application can handle high levels of traffic. The use of ALB is particularly useful when running applications that receive unpredictable amounts of traffic and need to scale dynamically.