-1

A workload in an Amazon VPC consist of a single web-server launched from a custom AMI.Session state is stored in database. How should the Solutions Architect modify this workload to be both highly available and scalable?

I am hesitating between A and C. Lots of my friends, including me, prefer C. But why the answer is A from an unofficial testing agency? Is the agency wrong?

A. Create a launch configuration with a desired capacity of two web servers across multiple Availability Zones. Create an Auto Scaling group with the AMI ID of the web server image. Use Amazon Route 53 latency-based routing to balance traffic across the Auto Scaling group.

B. Create a launch configuration with the AMI ID of the web server image. Create an Auto Scaling group using the newly-created launch configuration, and a desired capacity of two web servers across multiple regions. Use an Application Load Balancer (ALB) to balance traffic across the Auto Scaling group.

C. Create a launch configuration with the AMI ID of the web server image. Create an Auto Scaling group using the newly-created launch configuration, and a desired capacity of two web servers across multiple Availability Zones. Use an ALB to balance traffic across the Auto Scaling group.

D.Create a launch configuration with the AMI ID of the web server image. Create an Auto Scaling group using the newly-created launch configuration, and a desired capacity of two web servers across multiple Availability Zones. Use Route 53 weighted routing to balance traffic across the Auto Scaling group.

Chauncy Yin
  • 1
  • 2
    Welcome to StackOverflow. This site is intended to answer specific programming questions. You can look at https://stackoverflow.com/help/how-to-ask – Alfredo A. Nov 01 '18 at 15:30
  • 1
    I'm voting to close this question as off-topic because this appears to be a question from an AWS Certification exam or pre-test – chris Nov 01 '18 at 18:48

2 Answers2

0

Choice A cannot be correct. Where did you see this question (and answer)?

This question requires knowledge of how Auto Scaling (AS) works:

  1. AS launch configurations have an AMI id
  2. AS groups have desired capacity and a launch configuration
  3. AS groups contain EC2 instances from multiple AZs within a region, but not multiple regions

So, applying that knowledge to the available choices:

  • A is incorrect because a launch configuration does not have a desired capacity
  • B is incorrect because AS groups are cross AZ, not cross region

So, the only possible correct choices are C and D. At that point you need to decide if cross-AZ ALB is correct vs Route 53 weighted routing.

jarmod
  • 71,565
  • 16
  • 115
  • 122
0

Is this an exam question??

The Correct answer is C.

The architecture is like Internet->Route53 (points to ALB Endpoint)->ALB->ASG Instances

The other choices cannot be correct

A) This statement is wrong. It doesn't make any sense to use latency based routing when you use only one ALB.

B) You cannot use multiple regions in the same Auto Scaling Group.

D) Same as A

Mohammad Ghonaim
  • 385
  • 2
  • 10