SOA-C02 Question 88
Select 3A company is deploying a critical web application on AWS and wants to ensure high availability and fault tolerance. They are considering whether to use a single Availability Zone (AZ) or a Multi-AZ deployment for their Amazon RDS database and Amazon EC2 instances. Which of the following considerations should guide their decision?
- A
Multi-AZ deployment ensures that the application remains available even if an entire Availability Zone fails.
- B
Single Availability Zone deployment provides the lowest latency for all users accessing the application.
- C
Amazon RDS Multi-AZ deployment automatically replicates data to a standby instance in another Availability Zone.
- D
Multi-AZ deployment is typically more cost-effective than Single-AZ deployment.
- E
Using a Multi-AZ Amazon EC2 Auto Scaling group ensures that instances are distributed across multiple Availability Zones.
Show answer and explanation
Correct answers: A, C, E
Explanation
Multi-AZ deployments are critical for applications requiring high availability and fault tolerance. By distributing resources across multiple Availability Zones, AWS services such as Amazon RDS and EC2 Auto Scaling groups can help ensure service continuity in the event of an AZ failure. Single-AZ deployments, while cost-effective and sometimes offering lower latency, do not provide the same level of protection against AZ failures.
- A. Correct.
Correct: Multi-AZ deployment is designed for high availability. If one AZ becomes unavailable, resources in another AZ can take over to ensure application uptime.
- B. Incorrect.
Incorrect: Single Availability Zone may provide lower latency for users in that specific AZ, but it does not ensure high availability or fault tolerance.
- C. Correct.
Correct: Amazon RDS Multi-AZ deployment replicates data synchronously to a standby instance in another AZ, providing increased durability and availability.
- D. Incorrect.
Incorrect: Multi-AZ deployments are generally more expensive than Single-AZ due to the additional resources and replication mechanisms involved.
- E. Correct.
Correct: When using a Multi-AZ Amazon EC2 Auto Scaling group, EC2 instances can be distributed across multiple AZs, which improves fault tolerance and availability.