AWS Certified SysOps Administrator – AssociateReliability and Business ContinuityEasy
A company is running a critical application on Amazon EC2 instances in a single Availability Zone. The application processes real-time financial transactions and requires high availability. The company wants to improve the application's resilience to Availability Zone failures without significantly re-architecting the application. Which AWS service or feature should a SysOps Administrator recommend?
- AMigrate the application to AWS Lambda functions across multiple Availability Zones.
- BSet up an Amazon CloudFront distribution with multiple origin failover configurations.
- CConfigure an Auto Scaling group to distribute EC2 instances across multiple Availability Zones.
- DImplement Amazon S3 Cross-Region Replication for application data.
Show answer & explanationAnswer & explanation
Correct answer: C. Configure an Auto Scaling group to distribute EC2 instances across multiple Availability Zones.
Distributing EC2 instances across multiple Availability Zones using an Auto Scaling group is a fundamental and effective way to achieve high availability and protect against single Availability Zone failures for EC2-based applications without extensive re-architecting.
Why the other options are wrong
- A. Migrating to Lambda would be a significant re-architecture, which the question explicitly states to avoid.
- B. CloudFront is a CDN and while it can improve performance and edge availability, it doesn't solve compute resilience against AZ failures directly for the backend application.
- D. S3 replication addresses data durability, not compute availability for an active application.
Multi-AZ Deployment (EC2)
Distributing application resources, such as EC2 instances, across multiple Availability Zones within a region to ensure high availability and fault tolerance.
- Protects against single Availability Zone failures.
- Achieved using Auto Scaling Groups and Load Balancers.
- Increases resilience without requiring complex re-architecture for many applications.
Memory trick: Spread your servers, spread your smiles, across the zones for miles!