What is AWS AutoScaling?

AWS AutoScaling

AWS AutoScaling is an AWS service that allows you to maintain the availability of applications by Amazon EC2 scaling capacity up or down according to the condition set. The advantage of deploying applications on a cloud gives you the ability to launch and then release servers in response to volatile workloads.

Why do we need AutoScaling?

To build a highly available application, auto-scaling is used to avoid the single instance of failure by distributing traffic across availability zones. It eliminates the chance of failure by implementing the new instance, so the smooth running of application is possible.

AutoScaling enables us to adjust infrastructure according to the throughput needs. This service automatically adds servers for high throughput and terminate a few instances when traffic goes down. It provides a cost-effective way of scaling depending on traffic behavior.

Components of AWS AutoScaling

• Auto-Scaling Group: Auto-Scaling Group is a group of Amazon EC2 instances, which is managed by the Auto-Scaling Group service. Every Scaling group has configuration options, which control when the auto scaling should terminate and launch new instances
• Scaling Policy: AutoScaling can be adjusted dynamically by associating Scaling policies and Amazon CloudWatch alarms with an Auto-Scaling Group. When the threshold is crossed, Amazon CloudWatch automatically sends alarms to trigger scaling in or out to the number of EC2 instances that are currently receiving the traffic behind the load balancer
• Launch Configuration: Auto-Scaling Groups use a launch configuration as a template for the EC2 instance to specify which AMI will be launched, which key pair will be used, and what instance type.

Benefits of AWS AutoScaling

AWS  AutoScaling has a number of benefits. Some of which are listed below:

·         Better Fault Torelance: AutoScaling determines when the instances are unhealthy or terminated and launches an instance immediately to replace it. You can also use AutoScaling to configure multiple availability design instances. If one availability design terminates, the auto scaling launches another instance to compensate for the availability design

·         Better Availability: AutoScaling also gives you better availability as the application always has the right amount of computing capacity to handle the traffic

·         Better Cost Management: AutoScaling provides better cost management as you can scale up and down according to demand. You can save money by early launching the instances, as they are required and terminate them when they are no longer in use.

Situation

A Software Architect deployed a web application architecture. The application is running on one EC2 instance. As the customer traffic load increases, the instance becomes overloaded, thus affecting the performance and creating latency in the response. What should the Architect do to handle customer requests and provide high availability of service?

Solution

A more scalable way of avoiding the overloaded instance is to use the AWS EC2 AutoScaling service. This service automatically launches more instance in order to balance the traffic loads.  The procedure for the launch of EC2 instance is defined in the following step-by-step guide.

Step-by-Step Guide

1. Log in to the AWS Console Management and click on “EC2” from the “Compute” option.
2. The “EC2” tab will appear. Click on “Auto Scaling Groups” from the navigation bar.
3. Click on “Create Auto Scaling group”.
4. Now, click on “Get Started” to launch the configuration.
5. The tab of “Create Launch Configuration” will open.
6. Click on “Select” from the “Choose AMI” tab.
7. “Choose Instance Type” tab will appear.
8. Select the instance type of your choice.
9. Then click “Next: Configure details”.
10. Now, create a launch configuration by entering the name.
11. Click on “Next: Add Storage”.
12. Click on “Next: Configure Security Group”.
13. Enable “Create a new security group”.
14. Click on “Review”.
15. Click “Create launch configuration”.
16. Select a “Create a new key pair” from the first tab.
17. Write a name in the box “Key pair name”.
18. Click “Download Key Pair”.
19. Click “Create launch configuration”.
20. Now, enter a name in the box “Group name”.
21. Enter the required subnet.
22. Click on “Next: Configure scaling policies”.
23. Click on “Next: Configure Notification”.
24. Click on “Next: Configure Tags”.
25. Enter the key and value.
26. Click on “Review”.
27. All the entered and selected details will appear.
28. Click on “Create Auto Scaling group”.
29. The launch configuration will now appear with the group name.
30. To check the instance details, click on the “Instance” option.
31. The details of the launched instance will appear.

    Conclusion

    With AWS AutoScaling service, the Architect can easily launch the configuration of the new instance to overcome the problem of overload that is affecting the system performance and creating delayed response. The lab guides the launching scenario of the EC2 instance so that auto-scaling service can automatically launch a new instance whenever there are high workloads and terminate the instance when the load goes down.