Amazon Web Services - Auto Scaling and Elastic Load Balancing

Explore AWS Auto Scaling and Elastic Load Balancing features to optimize application performance, cost-efficiency, and fault tolerance. Learn how to set up and manage load balancers and auto-scaling groups.

AWS Auto Scaling

Auto Scaling in AWS allows you to automatically adjust the number of Amazon EC2 instances based on the demand for your application. By setting parameters such as the minimum and maximum number of instances, Auto Scaling helps maintain application performance during traffic spikes and reduces costs during low-demand periods.

How AWS Auto Scaling Works

Auto Scaling increases the number of EC2 instances as demand rises and decreases them when demand drops.

Use Cases for Auto Scaling

Ideal for applications with fluctuating usage patterns (hourly, daily, or weekly).

Enabled By Amazon CloudWatch

Auto Scaling is powered by Amazon CloudWatch, which monitors metrics like CPU utilization and network traffic. It’s available at no extra cost.

Elastic Load Balancing (ELB)

Elastic Load Balancing automatically distributes incoming traffic across multiple EC2 instances, improving fault tolerance and ensuring your application remains available even during failures.

Components of Elastic Load Balancing

  • Load Balancer: Handles and distributes incoming requests to EC2 instances.
  • Control Service: Automatically scales the handling capacity by adding or removing load balancers based on traffic demands and checks the health of instances.
  • SSL Termination: Offloads the SSL processing from EC2 instances, freeing up resources. An X.509 certificate is required for SSL termination.

Features of Elastic Load Balancing

  • Scalability: Designed to handle unlimited requests per second with a gradually increasing load.
  • Configuration: EC2 instances and load balancers can be configured to accept traffic as needed.
  • Flexibility: Load balancers can be added or removed without disrupting the flow of information.
  • Multi-AZ Support: ELB can distribute traffic within a single Availability Zone or across multiple zones, enhancing application performance.

Creating and Managing Load Balancers

Steps to Create a Load Balancer

  1. Go to EC2 Console: Access the EC2 console using this link: EC2 Console.
  2. Select Load Balancers: From the navigation pane, choose "Load Balancers" and click "Create Load Balancer."
  3. Enter Details: Provide the load balancer's name and select the network where your instances are hosted.
  4. Enable Advanced VPC Configuration (Optional): If using a default VPC, select this option to choose specific subnets.
  5. Assign Security Groups: Follow the instructions to assign security groups to your load balancer.
  6. Configure Health Checks: Set up health check parameters to monitor instance health.
  7. Add EC2 Instances: Choose the EC2 instances to register with the load balancer.
  8. Add Tags (Optional): Assign tags to your load balancer for easier management.
  9. Review and Create: Verify your settings, make any necessary adjustments, and create the load balancer.

Steps to Delete a Load Balancer

  1. Go to EC2 Console: Access the EC2 console.
  2. Select Load Balancers: In the navigation pane, choose "Load Balancers."
  3. Choose Load Balancer: Select the load balancer you want to delete and click the "Action" button.
  4. Delete: Click "Delete," confirm by clicking "Yes, Delete," and the load balancer will be removed.

Benefits of Combining Auto Scaling with Elastic Load Balancing

Auto Scaling combined with Elastic Load Balancing ensures that your applications remain responsive, fault-tolerant, and cost-effective, automatically adjusting to meet the needs of your users.