SAP-C02 Design for New Solutions Practice Question

A company is designing a new multi-tier application on AWS. The application will use an Application Load Balancer (ALB) to distribute traffic to Amazon EC2 instances in an Auto Scaling group. The company requires that the application be highly available across multiple Availability Zones and that it can scale automatically based on demand. The company also wants to ensure that the application can handle sudden spikes in traffic without manual intervention. Which two actions should a solutions architect recommend to meet these requirements? (Choose two.)

⚠ Common exam trap

The trap here is assuming that a Network Load Balancer or cross-zone load balancing alone can provide high availability, when in fact the Auto Scaling group must be configured across multiple AZs with sufficient minimum capacity.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Create a target tracking scaling policy based on average CPU utilization to automatically adjust the number of instances.

To achieve high availability, the Auto Scaling group must span multiple Availability Zones with a minimum capacity of at least two instances. To handle sudden spikes automatically, a target tracking scaling policy based on a metric like CPU utilization dynamically adjusts capacity. Together, these actions provide both resilience and elasticity without manual intervention.

Answer analysis

Option-by-option breakdown

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

✗
Enable cross-zone load balancing on the ALB and configure the Auto Scaling group to use a single Availability Zone.
Why it's wrong here
Cross-zone load balancing distributes traffic evenly across all registered targets in all enabled AZs, but if the Auto Scaling group uses a single AZ, the application is not highly available. An AZ failure would take down all instances. This option fails the high availability requirement.
✗
Use a Network Load Balancer (NLB) instead of an Application Load Balancer (ALB) to improve performance.
Why it's wrong here
The application is multi-tier and likely uses HTTP/HTTPS, where ALB provides layer 7 features such as path-based routing and host-based routing. NLB operates at layer 4 and does not provide these features. While NLB can handle high throughput, it is not the right choice for this scenario, and it does not address scaling or high availability directly.
✓
Create a target tracking scaling policy based on average CPU utilization to automatically adjust the number of instances.
Why this is correct
A target tracking scaling policy automatically scales the Auto Scaling group to maintain a target metric, such as average CPU utilization. This handles sudden spikes in traffic by adding instances as needed, and scales in during low demand, providing automatic scaling without manual intervention.
✓
Configure the Auto Scaling group to use multiple Availability Zones and set the minimum capacity to at least two instances.
Why this is correct
Spreading instances across multiple AZs ensures high availability. Setting a minimum capacity of at least two instances ensures that the application remains available even if one instance fails. This is a fundamental best practice for high availability in a multi-tier architecture.
✗
Configure a scheduled scaling policy to add instances at predicted peak times.
Why it's wrong here
Scheduled scaling is useful for predictable traffic patterns, but the scenario requires handling sudden spikes without manual intervention. Scheduled scaling requires you to define the schedule in advance and cannot react to unexpected spikes. Therefore, it does not meet the requirement for automatic scaling based on demand.

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SAP-C02 Design for New Solutions Practice Question

Why each option matters

Option-by-option breakdown

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