DOP-C02 Question 137
Select 3A company runs a mission-critical, customer-facing application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application must be highly available and resilient to regional failures. Which solution meets these requirements?
- A
Deploy EC2 instances in multiple Availability Zones (AZs) within a single AWS Region and attach them to the ALB.
- B
Use an Auto Scaling group to launch instances across multiple AWS Regions, with Route 53 configured for failover routing.
- C
Use an ALB in each AWS Region and configure Route 53 with weighted routing to distribute traffic between regions.
- D
Deploy EC2 instances in a single Availability Zone (AZ), and use a backup ALB in another AWS Region for failover.
- E
Use AWS Global Accelerator to direct traffic to ALBs in multiple AWS Regions for global resilience.
Show answer and explanation
Correct answers: B, C, E
Explanation
To implement a highly available and resilient solution, the architecture must span multiple AWS Regions to tolerate regional failures. Option 2 uses Auto Scaling groups and Route 53 failover routing for redundancy and resilience. Option 3 leverages multiple ALBs in different regions with Route 53 weighted routing for load distribution and failover. Option 5 uses AWS Global Accelerator to ensure low-latency, region-aware traffic routing, and resilience to regional failures. These options collectively meet the requirements for high availability and resilience.
- A. Incorrect.
This option provides high availability within a single region by using multiple AZs but does not meet the requirement for resilience to regional failures.
- B. Correct.
Using an Auto Scaling group across multiple AWS Regions ensures instances are launched in different regions, and Route 53 failover routing ensures traffic is redirected to the healthy region. This meets both high availability and regional resilience requirements.
- C. Correct.
This option ensures high availability and resilience by using separate ALBs in multiple regions. Weighted routing in Route 53 can distribute traffic across regions or failover in case of a regional failure.
- D. Incorrect.
Deploying EC2 instances in a single AZ does not provide high availability. Additionally, relying on a backup ALB in another region without automation for failover introduces delays and potential errors.
- E. Correct.
AWS Global Accelerator can route traffic to ALBs in multiple regions and ensures low latency and high availability by leveraging the AWS global network. This solution meets both high availability and regional resilience requirements.