High Availability for EC2 Instance: Ensuring No Downtime

Correct Answer: B.

You can create an Auto Scaling group using an existing EC2 instance in one of three ways.

Create a launch template from an existing EC2 instance.

Then use the launch template to create a new Auto Scaling group.

For this procedure, see Creating a launch template from an existing instance (console).

Use the console to create an Auto Scaling group from a running EC2 instance.

When you do this, Amazon EC2 Auto Scaling creates a launch configuration for you and associates it with the Auto Scaling group.

This method works well if you want to add the instance to the new Auto Scaling group where it can be managed by Amazon EC2 Auto Scaling.

For more information, see Attach EC2 instances to your Auto Scaling group.

Specify the ID of an existing EC2 instance in the API call that creates the Auto Scaling group.

This method is the subject of the following procedure.

Option A is incorrect because it leads to downtime by creating launch configuration, AMI, and Auto Scaling group.

Options C and D are incorrect because Elastic Beanstalk and Opswork stack are not easy methods and are very time-consuming.

For more information on creating a launch configuration from an existing instance, please visit the below URL-

https://docs.aws.amazon.com/autoscaling/ec2/userguide/create-asg-from-instance.html https://docs.aws.amazon.com/autoscaling/ec2/userguide/create-launch-template.html#create-launch-template-for-auto-scaling https://docs.aws.amazon.com/autoscaling/ec2/userguide/create-lc-with-instanceID.html#create-lc-with-defaultconfig

Option A is the easiest way to achieve high availability for the running instance while ensuring no downtime. Here's a detailed explanation of how it works:

1. Create an AMI from the running instance: An Amazon Machine Image (AMI) is a pre-configured virtual machine image that is used to create new EC2 instances. Creating an AMI from the running instance ensures that all the configurations, settings, and data on the current instance are saved.

2. Create a new launch configuration and an Auto Scaling group: A launch configuration is a template that contains information about the EC2 instance type, AMI ID, key pair, security groups, and other settings required to launch an EC2 instance. Creating a new launch configuration allows you to define the desired instance specifications and configuration.

An Auto Scaling group is a group of EC2 instances that are automatically launched and terminated based on demand. Creating an Auto Scaling group ensures that there is always a minimum number of running instances to handle traffic, and it automatically launches new instances if any existing instance fails.

3. Terminate the current instance and launch the Auto Scaling group to launch a new instance: Once you have created a new launch configuration and an Auto Scaling group, terminate the current instance. The Auto Scaling group will launch a new instance with the same configurations as the terminated instance, ensuring that there is no downtime.

Option B - Creating an Auto Scaling group from the running EC2 instance: This option is similar to Option A, but it requires you to create a new launch configuration first. The process of creating a new launch configuration requires you to stop the running instance, which can cause downtime.

Option C - Terminate the instance and launch it via an Elastic Beanstalk environment: Elastic Beanstalk is a fully managed service that makes it easy to deploy and run applications in multiple languages. While Elastic Beanstalk can help you achieve high availability, it is not the easiest way to do so. Terminating the instance and launching it via Elastic Beanstalk can cause downtime.

Option D - Terminate the instance and launch it via an Opswork stack: AWS OpsWorks is a configuration management service that helps you automate the deployment of applications. While OpsWorks can help you achieve high availability, it is not the easiest way to do so. Terminating the instance and launching it via OpsWorks can cause downtime.