When an Auto Scaling Group Is Running in Amazon Elastic

question 42

Multiple Choice

When an Auto Scaling group is running in Amazon Elastic Compute Cloud (EC2) , your application rapidly scales up and down in response to load within a 10-minute window; however, after the load peaks, you begin to see problems in your configuration management system where previously terminated Amazon EC2 resources are still showing as active. What would be a reliable and efficient way to handle the cleanup of Amazon EC2 resources within your configuration management system? (Choose two.)

• A) Write a script that is run by a daily cron job on an Amazon EC2 instance and that executes API Describe calls of the EC2 Auto Scaling group and removes terminated instances from the configuration management system.
• B) Configure an Amazon Simple Queue Service (SQS) queue for Auto Scaling actions that has a script that listens for new messages and removes terminated instances from the configuration management system.
• C) Use your existing configuration management system to control the launching and bootstrapping of instances to reduce the number of moving parts in the automation.
• D) Write a small script that is run during Amazon EC2 instance shutdown to de-register the resource from the configuration management system.
• E) Use Amazon Simple Workflow Service (SWF) to maintain an Amazon DynamoDB database that contains a whitelist of instances that have been previously launched, and allow the Amazon SWF worker to remove information from the configuration management system.

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Definitions:

Lateral Relations

The interactions and communications that occur among employees on the same hierarchical level within an organization.

Network Structure

A network structure links networks of outside suppliers and service contractors to a company’s core functions.

Operating Efficiency

The capability of an organization to deliver products or services in a cost-effective manner while maintaining quality.

Computerised Networking

The use of computer systems and digital technologies to establish connections and facilitate communication between individuals or organizations.