SOA-C02 Deployment, Provisioning, and Automation Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  A launch template or launch configuration that defines the AMI and instance type.

  Why this is correct

  A launch template or configuration is mandatory because the Auto Scaling group must know which Amazon Machine Image (AMI), instance type, key pair, and other instance settings to use when scaling out. Without a template, the ASG has no blueprint for creating EC2 instances, so it cannot launch or register anything with a load balancer. This is the fundamental instance-provisioning requirement, not merely an optional convenience.

• ✗

  A health check grace period set in the Auto Scaling group.

  Why it's wrong here

  The health check grace period is an ASG setting that controls how long after an instance launch the service waits before beginning health checks, protecting newly launched instances from being terminated before they can finish bootstrapping. It does not trigger, enable, or configure automatic registration with a target group; registration is independent of this timer. Even a grace period of zero would not prevent or require registration—it only affects when health checks start.

• ✗

  A security group that allows traffic from the ALB.

  Why it's wrong here

  A security group allowing traffic from the Application Load Balancer is a network-layer access control that permits incoming requests to reach the web instances, but it has no role in the registration process. The ASG automatically adds launched instances to the target group by their instance ID, not by their security group membership. Without permissive inbound rules the instances would receive no traffic, but they would still be registered and appear in the target group's health checks.

• ✓

  A target group ARN specified in the Auto Scaling group's configuration.

  Why this is correct

  When you specify a target group ARN in the Auto Scaling group configuration, you are telling the ASG to automatically attach every launched instance to that target group, which enables the load balancer to distribute traffic to them. This ARN is the actual integration point—it directs the registration and deregistration actions as instances scale in and out. The ALB's listener forwards requests to the target group, so without this ARN the ASG has no association with the load balancer.

• ✗

  An Application Load Balancer created in the same stack.

  Why it's wrong here

  Creating the Application Load Balancer in the same stack is not required; the ASG only needs the target group's Amazon Resource Name (ARN), which can reference a load balancer created in a different stack or even a different account/VPC via appropriate permissions. The physical location or creation context of the ALB is irrelevant to the automatic registration mechanism. The target group ARN is what establishes the connection, so the ALB itself is not a prerequisite in the ASG definition.

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