Architecting on AWS Certification Architecting on AWS Certification High Availability & Fault Tolerance 2

Question 1

Which AWS architectural principle recommends designing systems assuming that components will fail?

Accepted Answer

Design for failure

Answer

AWS Well-Architected Framework's reliability pillar advises designing systems to expect and automatically recover from component failures.

Question 2

An application uses DynamoDB and must remain available if an Availability Zone fails. Which DynamoDB feature handles this automatically?

Accepted Answer

DynamoDB built-in multi-AZ replication

Answer

DynamoDB automatically replicates data across three Availability Zones in a Region, providing built-in high availability with no additional configuration.

Question 3

Which AWS service can be used to implement a dead-letter queue to capture messages that repeatedly fail processing in an SQS-based architecture?

Accepted Answer

Amazon SQS itself

Answer

SQS supports dead-letter queues, which are separate SQS queues where messages that exceed the maxReceiveCount are automatically moved for later inspection.

Question 4

An architect must ensure an EC2-based application recovers automatically after an instance failure with the least operational effort. What is the best approach?

Accepted Answer

Place the instance in an Auto Scaling group with min=1

Answer

An Auto Scaling group with minimum capacity of 1 automatically launches a replacement instance if the existing one terminates or fails a health check.

Question 5

Which ELB listener rule action allows an Application Load Balancer to return a static error page when the backend targets are all unhealthy?

Accepted Answer

Fixed-response action

Answer

The ALB fixed-response action returns a custom HTTP response (status code + body) directly from the load balancer without routing to any target.

Architecting on AWS Certification Practice Test

Architecting on AWS Certification Practice Test

Architecting on AWS Certification Architecting on AWS Certification High Availability & Fault Tolerance 2