Understanding ASG behaviour

[Rumman]

For the question

A company needs to deploy at least 2 EC2 instances to support the normal workloads of

its application and automatically scale up to 6 EC2 instances to handle the peak load.

The architecture must be highly available and fault-tolerant as it is processing mission-critical

workloads.

As the Solutions Architect of the company, what should you do to meet the above

requirement?

The option that says: Create an Auto Scaling group of EC2 instances and set the

minimum capacity to 2 and the maximum capacity to 6. Use 2 Availability Zones and

deploy 1 instance for each AZ is incorrect because if an AZ outage occurred, there will

only be 1 running instance left. The scenario requires you to run at least 2 EC2 instances

to support the workload of their application.

But I am wondering if one of the AZ is gone why can’t ASG not been able to spin up two instances in the other AZ as we set a minimum cap to 2?

[Gerome-TutorialsDojo]

Hello Rumman,

Thanks for the feedback.

But I am wondering if one of the AZ is gone why can’t ASG not been able to spin up two instances in the other AZ as we set a minimum cap to 2?

— There is a statement in the scenario “processing mission-critical workloads” this means that there shouldn’t be a downtime. If you would recreate this option in the AWS Management Console, it takes a few minutes before ASG can spin up another instance in the remaining AZ. Therefore, if you need to run at least 2 EC2 instances to process mission-critical workloads, you must deploy 2 instances in each AZ. If there is an AZ outage, you would still have 2 instances running.

Let us know if you need further assistance. The Tutorials Dojo team is dedicated to helping you pass your AWS exam on your first try!

Regards,

Gerome @ Tutorials Dojo