Question 3
A company has a hybrid architecture solution in which some legacy systems remain on-premises, while a specific cluster of servers is moved to AWS. The company cannot reconfigure the legacy systems, so the cluster nodes must have a fixed hostname and local IP address for each server that is part of the cluster. The DevOps Engineer must automate the configuration for a six-node cluster with high availability across three Availability Zones (AZs), placing two elastic network interfaces in a specific subnet for each AZ. Each node's hostname and local IP address should remain the same between reboots or instance failures.
Which solution involves the LEAST amount of effort to automate this task?
Create an AWS Elastic Beanstalk application and a specific environment for each server of the cluster. For each environment, give the hostname, elastic network interface, and AZ as input parameters. Use the local health agent to name the instance and attach a specific elastic network interface based on the current environment.
Create a reusable AWS CloudFormation template to manage an Amazon EC2 Auto Scaling group with a minimum size of 1 and a maximum size of 1. Give the hostname, elastic network interface, and AZ as stack parameters. Use those parameters to set up an EC2 instance with EC2 Auto Scaling and a user data script to attach to the specific elastic network interface. Use CloudFormation nested stacks to nest the template six times for a total of six nodes needed for the cluster, and deploy using the master template.
Create an Amazon DynamoDB table with the list of hostnames, subnets, and elastic network interfaces to be used. Create a single AWS CloudFormation template to manage an Auto Scaling group with a minimum size of 6 and a maximum size of 6. Create a programmatic solution that is installed in each instance that will lock/release the assignment of each hostname and local IP address, depending on the subnet in which a new instance will be launched.
Create a reusable AWS CLI script to launch each instance individually, which will name the instance, place it in a specific AZ, and attach a specific elastic network interface. Monitor the instances, and in the event of failure, replace the missing instance manually by running the script again.
Correct answer: B
Explanation:
https://aws.amazon.com/pt/blogs/devops/use-nested-stacks-to-create-reusable-templates-and-support-role-specialization/
https://aws.amazon.com/pt/blogs/devops/use-nested-stacks-to-create-reusable-templates-and-support-role-specialization/