An application consists of a fleet of EC2 Instances.
These Instances are launched in the Oregon (us-west-2) region which consists of 3 availability zones.
This application needs 6 Instances running at all times.
As an architect, you need to distribute the instances so that the application could still maintain its capacity if any one of the availability zone goes down.
Also, you need to ensure that the cost is kept to a minimum? Which of the following configurations would you consider?
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - D.
So now, let's look at.
Option A.If any availability zone goes down, we will have a total of 12 instances running.
This is an additional 6 over the requirement of the question and will result in a higher cost.
So now, let's look at Option.
B.If the availability zone us-west-2a goes down, then you will have only 3 instances running.
Because the other 3 instances are running in the us-east-2c region.
So now, let's look at Option.
C.If either us-west-2b or us-west-2c availability zone goes down, we will have a total of 9 instances running.
This is an additional 3 over the requirement of the question and will result in a higher cost.
So now, let's look at Option.
D.If either us-east-2a or us-west-2b or us-west-2c availability zone goes down, there will be a total of 6 instances running, which is what we need.
For more information on Regions and Availability zones, please refer to the below URL-
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.htmlTo ensure high availability and fault tolerance, it is recommended to distribute the instances across multiple availability zones in a region. If any one of the availability zones goes down, the application will still be able to operate with the remaining instances in the other availability zones.
In this scenario, the application needs 6 instances running at all times. To ensure high availability and fault tolerance, it is recommended to have at least 2 instances running in each availability zone. Therefore, options A and D are the most suitable because they both have 6 instances distributed across all 3 availability zones.
Option B only has 3 instances running in 2 availability zones, which does not provide enough redundancy in case one of the availability zones goes down. Option C has 6 instances running in one availability zone, which could create a single point of failure if that availability zone goes down.
Therefore, option A and D are the most suitable. However, since the question asks for the option that would keep costs to a minimum, option D would be the most cost-effective as it only requires a total of 9 instances instead of 18 in option A.
Option D is the best configuration as it has 3 instances running in each availability zone. This would provide high availability and fault tolerance while keeping costs to a minimum.