SOA-C02 Question 50
Select 2Your company runs a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application uses Amazon RDS for its database, and all resources are in a single Availability Zone. During a recent outage in the Availability Zone, the application became inaccessible. As a SysOps Administrator, how can you improve the application's reliability and ensure high availability in the event of future outages?
- A
Deploy the EC2 instances across multiple Availability Zones and configure the ALB to distribute traffic across them.
- B
Enable Multi-AZ deployment for the Amazon RDS database.
- C
Increase the instance size of the EC2 instances to handle more traffic.
- D
Set up Amazon CloudFront to cache application content and reduce dependency on the backend systems.
- E
Configure an Auto Scaling group to ensure the EC2 instances are replaced automatically if they fail.
Show answer and explanation
Correct answers: A, B
Explanation
To improve the application's reliability and ensure high availability, it is essential to distribute resources across multiple Availability Zones. Deploying EC2 instances in multiple zones and enabling Multi-AZ deployment for Amazon RDS ensures that the application can continue functioning during an Availability Zone outage. These configurations provide redundancy and failover capabilities, which are critical for maintaining business continuity.
- A. Correct.
Correct: Deploying EC2 instances across multiple Availability Zones ensures that the application can remain available even if one Availability Zone experiences an outage. The ALB will distribute traffic to healthy instances in other zones.
- B. Correct.
Correct: Enabling Multi-AZ deployment for Amazon RDS ensures that a standby database is available in another Availability Zone. This provides automatic failover in case the primary database becomes unavailable.
- C. Incorrect.
Incorrect: Increasing the instance size does not address the underlying issue of Availability Zone failure. It only increases the capacity of a single instance, which does not improve reliability during outages.
- D. Incorrect.
Incorrect: While Amazon CloudFront can help reduce traffic to backend systems, it does not address high availability or reliability in the event of an Availability Zone outage.
- E. Incorrect.
Incorrect: Auto Scaling replaces failed instances, but it does not protect against an entire Availability Zone outage if all instances are deployed in a single zone.