AWS Associate Certified Developer - Associate 3 — Questions and Answers
Question 1: A developer stores session data in ElastiCache Redis. The application needs to handle Redis connection failures gracefully. What is the recommended pattern?
- Terminate the application on connection failure
- Fall back to DynamoDB for session storage
- Implement circuit breaker with fallback to stateless processing (Correct answer)
- Store sessions in the EC2 instance store
Correct answer: Implement circuit breaker with fallback to stateless processing
A circuit breaker pattern detects failures and falls back gracefully, preventing cascading failures while maintaining availability.
Question 2: Which AWS service should a developer use to automatically rotate database credentials without modifying application code?
- AWS Systems Manager Parameter Store
- AWS Secrets Manager (Correct answer)
- AWS KMS
- AWS IAM roles
Correct answer: AWS Secrets Manager
AWS Secrets Manager natively integrates with RDS, Redshift, and DocumentDB to automatically rotate credentials on a schedule.
Question 3: A CloudFormation stack deployment fails midway. What happens to previously created resources by default?
- They remain and the stack enters UPDATE_FAILED state
- They are rolled back and deleted
- They are retained and the stack enters ROLLBACK_COMPLETE state (Correct answer)
- They are tagged for manual cleanup
Correct answer: They are retained and the stack enters ROLLBACK_COMPLETE state
By default, CloudFormation rolls back all changes on failure, deleting resources created during the failed deployment and entering ROLLBACK_COMPLETE.
Question 4: A developer needs to trigger a Lambda function whenever an item is modified in a DynamoDB table. What should they enable?
- DynamoDB Accelerator (DAX)
- DynamoDB Streams (Correct answer)
- DynamoDB global tables
- DynamoDB on-demand capacity
Correct answer: DynamoDB Streams
DynamoDB Streams captures item-level changes and can trigger Lambda functions to process each change record.
Question 5: An API Gateway REST API must only be accessible from within a VPC. Which endpoint type should be configured?
- Edge-optimized endpoint
- Regional endpoint
- Private endpoint (Correct answer)
- Cross-origin endpoint
Correct answer: Private endpoint
Private API Gateway endpoints are accessible only from within a VPC using a VPC endpoint (PrivateLink), blocking public internet access.
Question 6: A developer notices a Lambda function's cold start latency is too high. Which strategy MOST directly reduces cold start duration?
- Increase the Lambda timeout value
- Enable provisioned concurrency (Correct answer)
- Attach the Lambda to a VPC
- Use an ARM-based architecture
Correct answer: Enable provisioned concurrency
Provisioned concurrency pre-initializes execution environments, eliminating cold start latency for the configured number of instances.
Question 7: When using AWS X-Ray to trace a distributed application, what does a segment represent?
- A single AWS region where requests are processed
- Work done by a single service or application for a request (Correct answer)
- A group of related traces aggregated over time
- An error or fault detected in the application
Correct answer: Work done by a single service or application for a request
An X-Ray segment records data about work done by a single service, including timing, HTTP data, and any subsegments for downstream calls.
AWS Associate Certified Developer - Associate 3
A developer stores session data in ElastiCache Redis.
The application needs to handle Redis connection failures gracefully.
What is the recommended pattern?