SAA-C03 Question 433
Select 3A company is running a critical web application on Amazon EC2 instances behind an Elastic Load Balancer (ELB). The application stores user-uploaded files in an Amazon S3 bucket and uses Amazon RDS for its database. The company has recently experienced a regional outage, and they want to ensure that the application is highly available and can withstand regional failures in the future. What is the best solution to achieve this?
- A
Set up an Auto Scaling group for EC2 instances across multiple Availability Zones within the same region.
- B
Enable cross-region replication for the Amazon S3 bucket to replicate data to another region.
- C
Deploy the application in a separate region and configure Route 53 with a failover routing policy.
- D
Enable Multi-AZ deployments for the Amazon RDS database.
- E
Configure the Elastic Load Balancer to span multiple regions.
Show answer and explanation
Correct answers: B, C, D
Explanation
To ensure high availability across regions, the solution must address both data replication and failover mechanisms. Cross-region replication for Amazon S3 ensures that data is available in another region, while deploying the application in a separate region and configuring Route 53 with a failover routing policy provides the ability to switch traffic to the secondary region during a regional failure. Enabling Multi-AZ for Amazon RDS ensures high availability within a region and is essential for minimizing downtime during localized failures.
- A. Incorrect.
While using an Auto Scaling group across multiple Availability Zones improves availability within a single region, it does not address regional failures. This option alone is insufficient for cross-region high availability.
- B. Correct.
Enabling cross-region replication for Amazon S3 ensures that the data stored in the bucket is replicated to another region, providing durability and availability in case of a regional outage.
- C. Correct.
Deploying the application in a separate region and configuring Route 53 with a failover routing policy ensures that traffic is routed to the secondary region in the event of a regional failure, achieving high availability across regions.
- D. Correct.
Enabling Multi-AZ deployments for Amazon RDS ensures that the database is highly available within a region and can failover to a secondary AZ in case of an AZ failure. While this does not protect against regional failures, it is critical for high availability.
- E. Incorrect.
Elastic Load Balancers cannot span multiple regions. Each ELB is regional, so this option is not valid for achieving cross-region high availability.