A developer created an AWS Lambda function that performs a series of operations that involve multiple AWS services. The function's duration time is higher than normal. To determine the cause of the issue, the developer must investigate traffic between the services without changing the function code.
Which solution will meet these requirements?
A. Enable AWS X-Ray active tracing in the Lambda function. Review the logs in X-Ray.
B. Configure AWS CloudTrail. View the trail logs that are associated with the Lambda function.
C. Review the AWS Config logs in Amazon CloudWatch.
D. Review the Amazon CloudWatch logs that are associated with the Lambda function.
Show Answer
Correct Answer: A
Explanation: AWS X-Ray provides distributed tracing that shows end-to-end request flow and latency across AWS services invoked by a Lambda function. Enabling active tracing requires no code changes and allows the developer to identify which downstream service calls contribute to increased duration. CloudTrail, AWS Config, and standard CloudWatch logs do not provide detailed inter-service latency tracing.
Question 243
A company has a social media application that receives large amounts of traffic. User posts and interactions are continuously updated in an Amazon RDS database. The data changes frequently, and the data types can be complex. The application must serve read requests with minimal latency.
The application's current architecture struggles to deliver these rapid data updates efficiently. The company needs a solution to improve the application's performance.
Which solution will meet these requirements?
A. Use Amazon DynamoDB Accelerator (DAX) in front of the RDS database to provide a caching layer for the high volume of rapidly changing data.
B. Set up Amazon S3 Transfer Acceleration on the RDS database to enhance the speed of data transfer from the databases to the application.
C. Add an Amazon CloudFront distribution in front of the RDS database to provide a caching layer for the high volume of rapidly changing data.
D. Create an Amazon ElastiCache for Redis cluster. Update the application code to use a write-through caching strategy and read the data from Redis.
Show Answer
Correct Answer: D
Explanation: The application requires ultra-low-latency reads for frequently changing, complex data stored in Amazon RDS. Amazon ElastiCache for Redis is designed for this use case, providing an in-memory data store with microsecond-level read latency. A write-through caching strategy keeps Redis and RDS synchronized, ensuring data freshness while offloading read traffic from RDS. DAX works only with DynamoDB (not RDS), CloudFront and S3 Transfer Acceleration are not suitable for caching dynamic database queries, making Redis the correct solution.
Question 244
A company's developer has deployed an application in AWS by using AWS CloudFormation. The CloudFormation stack includes parameters in AWS Systems Manager Parameter Store that the application uses as configuration settings. The application can modify the parameter values.
When the developer updated the stack to create additional resources with tags, the developer noted that the parameter values were reset and that the values ignored the latest changes made by the application. The developer needs to change the way the company deploys the CloudFormation stack. The developer also needs to avoid resetting the parameter values outside the stack.
Which solution will meet these requirements with the LEAST development effort?
A. Modify the CloudFormation stack to set the deletion policy to Retain for the Parameter Store parameters.
B. Create an Amazon DynamoDB table as a resource in the CloudFormation stack to hold configuration data for the application. Migrate the parameters that the application is modifying from Parameter Store to the DynamoDB table.
C. Create an Amazon RDS DB instance as a resource in the CloudFormation stack. Create a table in the database for parameter configuration. Migrate the parameters that the application is modifying from Parameter Store to the configuration table.
D. Modify the CloudFormation stack policy to deny updates on Parameter Store parameters.
Show Answer
Correct Answer: D
Explanation: The parameter values are being reset during stack updates because CloudFormation continues to manage and update the AWS::SSM::Parameter resource based on the template, overwriting changes made by the application. DeletionPolicy: Retain only applies when a resource is deleted or replaced, not when it is updated in place, so it does not prevent value resets during normal updates. Using a stack policy to deny updates on the Parameter Store resources prevents CloudFormation from modifying those parameters during stack updates, while still allowing the application to change them. This meets the requirement with the least development effort.
Question 245
A developer is deploying a company's application to Amazon EC2 instances. The application generates gigabytes of data files each day. The files are rarely accessed, but the files must be available to the application's users within minutes of a request during the first year of storage. The company must retain the files for 7 years.
How can the developer implement the application to meet these requirements MOST cost-effectively?
A. Store the files in an Amazon S3 bucket. Use the S3 Glacier Instant Retrieval storage class. Create an S3 Lifecycle policy to transition the files to the S3 Glacier Deep Archive storage class after 1 year.
B. Store the files in an Amazon S3 bucket. Use the S3 Standard storage class. Create an S3 Lifecycle policy to transition the files to the S3 Glacier Flexible Retrieval storage class after 1 year.
C. Store the files on an Amazon Elastic Block Store (Amazon EBS) volume. Use Amazon Data Lifecycle Manager (Amazon DLM) to create snapshots of the EBS volumes and to store those snapshots in Amazon S3.
D. Store the files on an Amazon Elastic File System (Amazon EFS) mount. Configure EFS lifecycle management to transition the files to the EFS Standard- Infrequent Access (Standard-IA) storage class after 1 year.
Show Answer
Correct Answer: A
Explanation: The data is large, rarely accessed, and must be retrievable within minutes during the first year, then retained for long-term archival. Amazon S3 Glacier Instant Retrieval is designed for rarely accessed data with millisecond access, making it cost-effective compared to S3 Standard while meeting the access-time requirement. After one year, transitioning to S3 Glacier Deep Archive provides the lowest-cost storage for long-term (7-year) retention. Other options are more expensive (S3 Standard, EFS, EBS) or do not meet cost and access requirements as effectively.
Question 246
A developer is investigating an issue in part of a company's application. In the application, messages are sent to an Amazon Simple Queue Service (Amazon SQS) queue. The AWS Lambda function polls messages from the SQS queue and sends email messages by using Amazon Simple Email Service (Amazon SES). Users have been receiving duplicate email messages during periods of high traffic.
Which reasons could explain the duplicate email messages? (Choose two.)
A. Standard SQS queues support at-least-once message delivery.
B. Standard SQS queues support exactly-once processing, so the duplicate email messages are because of user error.
C. Amazon SES has the DomainKeys Identified Mail (DKIM) authentication incorrectly configured.
D. The SQS queue's visibility timeout is lower than or the same as the Lambda function's timeout.
E. The Amazon SES bounce rate metric is too high.
Show Answer
Correct Answer: A, D
Explanation: Standard SQS queues provide at-least-once delivery, so the same message can be delivered more than once, especially under high traffic. Additionally, if the SQS visibility timeout is less than or equal to the Lambda function's timeout, a message can become visible again and be processed by another Lambda invocation before the first one finishes, resulting in duplicate emails.
Question 247
A data visualization company wants to strengthen the security of its core applications. The applications are deployed on AWS across its development, staging, pre-production, and production environments. The company needs to encrypt all of its stored sensitive credentials. The sensitive credentials need to be automatically rotated. A version of the sensitive credentials need to be stored for each environment.
Which solution will meet these requirements in the MOST operationally efficient way?
A. Configure AWS Secrets Manager versions to store different copies of the same credentials across multiple environments.
B. Create a new parameter version in AWS Systems Manager Parameter Store for each environment. Store the environment-specific credentials in the parameter version.
C. Configure the environment variables in the application code. Use different names for each environment type.
D. Configure AWS Secrets Manager to create a new secret for each environment type. Store the environment-specific credentials in the secret.
Show Answer
Correct Answer: D
Explanation: AWS Secrets Manager provides encryption at rest, fine-grained access control, and built-in automatic rotation. Creating a separate secret per environment cleanly isolates credentials, supports environment-specific rotation, and is the most operationally efficient approach. Parameter Store lacks native automatic rotation, environment variables are insecure, and using versions of a single secret across environments complicates isolation and access control.
Question 248
A company runs an application on AWS. The application uses an AWS Lambda function that is configured with an Amazon Simple Queue Service (Amazon SQS) queue called high priority queue as the event source. A developer is updating the Lambda function with another SQS queue called low priority queue as the event source. The Lambda function must always read up to 10 simultaneous messages from the high priority queue before processing messages from low priority queue. The Lambda function must be limited to 100 simultaneous invocations.
Which solution will meet these requirements?
A. Set the event source mapping batch size to 10 for the high priority queue and to 90 for the low priority queue.
B. Set the delivery delay to 0 seconds for the high priority queue and to 10 seconds for the low priority queue.
C. Set the event source mapping maximum concurrency to 10 for the high priority queue and to 90 for the low priority queue.
D. Set the event source mapping batch window to 10 for the high priority queue and to 90 for the low priority queue.
Show Answer
Correct Answer: C
Explanation: The requirement is to prioritize processing from the high priority SQS queue while limiting total Lambda concurrency to 100. Lambda supports a per–event source mapping **maximum concurrency** setting for SQS. By setting maximum concurrency to 10 for the high priority queue and 90 for the low priority queue (and reserving 100 concurrency for the function), the high priority queue is guaranteed up to 10 concurrent Lambda invocations before the low priority queue can consume the remaining capacity. Batch size, delivery delay, and batch window do not control concurrency or prioritization across multiple SQS event sources.
Question 249
A company has an application that runs across multiple AWS Regions. The application is experiencing performance issues at irregular intervals. A developer must use AWS X-Ray to implement distributed tracing for the application to troubleshoot the root cause of the performance issues.
What should the developer do to meet this requirement?
A. Use the X-Ray console to add annotations for AWS services and user-defined services.
B. Use Region annotation that X-Ray adds automatically for AWS services. Add Region annotation for user-defined services.
C. Use the X-Ray daemon to add annotations for AWS services and user-defined services.
D. Use Region annotation that X-Ray adds automatically for user-defined services. Configure X-Ray to add Region annotation for AWS services.
Show Answer
Correct Answer: B
Explanation: For cross-Region distributed tracing with AWS X-Ray, Region annotations are required. X-Ray automatically adds Region annotations for AWS-managed services, but it does not do so for custom (user-defined) services. Therefore, the developer must instrument the user-defined services with the SDK to add the Region annotation, enabling X-Ray to correlate traces across multiple Regions and troubleshoot performance issues.
Question 250
A developer is creating an Amazon DynamoDB table by using the AWS CLI. The DynamoDB table must use server-side encryption with an AWS owned encryption key.
How should the developer create the DynamoDB table to meet these requirements?
A. Create an AWS Key Management Service (AWS KMS) customer managed key. Provide the key's Amazon Resource Name (ARN) in the KMSMasterKeyId parameter during creation of the DynamoDB table.
B. Create an AWS Key Management Service (AWS KMS) AWS managed key. Provide the key's Amazon Resource Name (ARN) in the KMSMasterKeyId parameter during creation of the DynamoDB table.
C. Create an AWS owned key. Provide the key's Amazon Resource Name (ARN) in the KMSMasterKeyId parameter during creation of the DynamoDB table.
D. Create the DynamoDB table with the default encryption options.
Show Answer
Correct Answer: D
Explanation: DynamoDB uses server-side encryption by default with an AWS owned key when no encryption parameters are specified. AWS owned keys are fully managed by AWS and do not require providing a KMS key ARN. Therefore, creating the table with the default encryption options satisfies the requirement to use server-side encryption with an AWS owned encryption key.
Question 251
A developer is creating a serverless application that uses an AWS Lambda function. The developer will use AWS CloudFormation to deploy the application. The application will write logs to Amazon CloudWatch Logs. The developer has created a log group in a CloudFormation template for the application to use. The developer needs to modify the CloudFormation template to make the name of the log group available to the application at runtime.
Which solution will meet this requirement?
A. Use the AWS::Include transform in CloudFormation to provide the log group's name to the application.
B. Pass the log group's name to the application in the user data section of the CloudFormation template.
C. Use the CloudFormation template's Mappings section to specify the log group's name for the application.
D. Pass the log group's Amazon Resource Name (ARN) as an environment variable to the Lambda function.
Show Answer
Correct Answer: D
Explanation: To make the log group name available to a Lambda function at runtime, the value must be passed into the function’s execution environment. CloudFormation can reference the created log group and inject its ARN (or name) as an environment variable on the Lambda function, which the code can read at runtime. AWS::Include is for importing template fragments, user data applies to EC2 (not Lambda), and Mappings are static and not exposed to the function at runtime.
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