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High-Availability Architecture: Choosing the Right AWS Services
Explore a common exam question about high-availability architecture for AWS Certified Solutions Architect - Associate. Understand your options.
A high-availability architecture is critical for applications that must remain operational during failures. Candidates often trip over which services best meet this requirement. Let's break down the question and options.
The question
A company is looking to implement a high-availability architecture for their application, which must remain operational even during failures. Which AWS services should they utilize to achieve this?
- A. Amazon EC2 with Auto Scaling and Elastic Load Balancing
- B. Amazon S3 and Amazon CloudFront
- C. AWS Lambda with Amazon RDS Multi-AZ
- D. Amazon Route 53 and AWS Direct Connect
Think before you scroll
When considering high availability, think about both fault tolerance and scalability. Which options ensure your application can handle traffic while remaining operational during outages? Don't rush your decision.
The answer
The correct option is A. Amazon EC2 with Auto Scaling and Elastic Load Balancing. This combination allows your application to automatically scale and distribute traffic across healthy instances, ensuring high availability even during failures.
Why the other options lose
- B. Amazon S3 and Amazon CloudFront: While these services provide high durability and caching for static content, they do not directly address server-side application availability. They are not suitable for dynamic applications requiring continuous uptime.
- C. AWS Lambda with Amazon RDS Multi-AZ: Although AWS Lambda can scale automatically and RDS Multi-AZ enhances database availability, this combination does not ensure complete application availability. An application often requires more than just database redundancy to remain operational.
- D. Amazon Route 53 and AWS Direct Connect: Route 53 is a DNS service that improves routing and availability but does not provide application-level fault tolerance. Direct Connect is a dedicated network connection and does not address application uptime either.
The concept behind it
High availability in cloud architecture means designing systems to remain functional and accessible despite failures. Using services that provide both scalability and fault tolerance is vital. Auto Scaling ensures your application can handle varying loads, while Elastic Load Balancing distributes traffic to healthy instances, preventing outages.
Exam trap to remember
Remember the two-question rule: always evaluate both scalability and fault tolerance when designing high-availability architectures. This will guide you to the correct answer in similar questions.