DOP-C02 Question 151
Select 3Your organization is running a critical e-commerce application hosted on AWS across multiple Availability Zones. The application leverages Amazon EC2 instances, an Application Load Balancer (ALB), and Amazon RDS for its backend database. To meet strict Service Level Agreements (SLAs) with your customers, you need to ensure a minimum uptime of 99.95% for the application. Which of the following strategies should you implement to meet or exceed this SLA?
- A
Deploy EC2 instances across at least two Availability Zones and place them behind the Application Load Balancer.
- B
Enable Multi-AZ deployment for the Amazon RDS instance.
- C
Use Amazon Route 53 health checks and DNS failover to redirect traffic in case of a regional outage.
- D
Implement Auto Scaling for the EC2 instances to handle traffic spikes.
- E
Configure a single Availability Zone for the entire application to reduce latency.
Show answer and explanation
Correct answers: A, B, C
Explanation
To meet or exceed a 99.95% SLA for your application, it is essential to design for high availability and fault tolerance. This includes distributing resources across multiple Availability Zones, leveraging Multi-AZ RDS for database durability, and implementing DNS failover with Route 53 to maintain uptime during regional disruptions. Auto Scaling is beneficial for performance but does not inherently guarantee availability, and relying on a single Availability Zone increases the risk of downtime.
- A. Correct.
Deploying EC2 instances across at least two Availability Zones ensures high availability and fault tolerance, meeting the SLA requirements.
- B. Correct.
Enabling Multi-AZ for Amazon RDS ensures database availability and automatic failover in case of an issue, contributing to the overall SLA compliance.
- C. Correct.
Using Amazon Route 53 health checks and DNS failover increases resiliency in case of a regional outage, providing an additional layer of high availability.
- D. Incorrect.
Implementing Auto Scaling is good for handling traffic spikes but does not directly address SLA requirements related to availability.
- E. Incorrect.
Configuring a single Availability Zone introduces a single point of failure, which is contrary to achieving the required SLA of 99.95% uptime.