DVA-C02 Online Practice Questions and Answers

A developer needs to migrate an online retail application to AWS to handle an anticipated increase in traffic. The application currently runs on two servers: one server for the web application and another server for the database. The web server renders webpages and manages session state in memory. The database server hosts a MySQL database that contains order details. When traffic to the application is heavy, the memory usage for the web server approaches 100% and the application slows down considerably.

The developer has found that most of the memory increase and performance decrease is related to the load of managing additional user sessions. For the web server migration, the developer will use Amazon EC2 instances with an Auto Scaling group behind an Application Load Balancer.

Which additional set of changes should the developer make to the application to improve the application's performance?

A. Use an EC2 instance to host the MySQL database. Store the session data and the application data in the MySQL database.

B. Use Amazon ElastiCache for Memcached to store and manage the session data. Use an Amazon RDS for MySQL DB instance to store the application data.

C. Use Amazon ElastiCache for Memcached to store and manage the session data and the application data.

D. Use the EC2 instance store to manage the session data. Use an Amazon RDS for MySQL DB instance to store the application data.

A company is planning to securely manage one-time fixed license keys in AWS. The company's development team needs to access the license keys in automaton scripts that run in Amazon EC2 instances and in AWS CloudFormation stacks. Which solution will meet these requirements MOST cost-effectively?

A. Amazon S3 with encrypted files prefixed with "config"

B. AWS Secrets Manager secrets with a tag that is named SecretString

C. AWS Systems Manager Parameter Store SecureString parameters

D. CloudFormation NoEcho parameters

A developer is writing a serverless application that requires an AWS Lambda function to be invoked every 10 minutes. What is an automated and serverless way to invoke the function?

A. Deploy an Amazon EC2 instance based on Linux, and edit its /etc/crontab file by adding a command to periodically invoke the Lambda function.

B. Configure an environment variable named PERIOD for the Lambda function. Set the value to 600.

C. Create an Amazon EventBridge rule that runs on a regular schedule to invoke the Lambda function.

D. Create an Amazon Simple Notification Service (Amazon SNS) topic that has a subscription to the Lambda function with a 600-second timer.

An application that is deployed to Amazon EC2 is using Amazon DynamoDB. The application calls the DynamoDB REST API. Periodically, the application receives a ProvisionedThroughputExceededException error when the application writes to a DynamoDB table.

Which solutions will mitigate this error MOST cost-effectively? (Choose two.)

A. Modify the application code to perform exponential backoff when the error is received.

B. Modify the application to use the AWS SDKs for DynamoDB.

C. Increase the read and write throughput of the DynamoDB table.

D. Create a DynamoDB Accelerator (DAX) cluster for the DynamoDB table.

E. Create a second DynamoDB table. Distribute the reads and writes between the two tables.

A company uses Amazon DynamoDB as a data store for its order management system. The company frontend application stores orders in a DynamoDB table. The DynamoDB table is configured to send change events to a DynamoDB

stream. The company uses an AWS Lambda function to log and process the incoming orders based on data from the DynamoDB stream.

An operational review reveals that the order quantity of incoming orders is sometimes set to 0. A developer needs to create a dashboard that will show how many unique customers this problem affects each day.

What should the developer do to implement the dashboard?

A. Grant the Lambda function's execution role permissions to upload logs to Amazon CloudWatch Logs. Implement a CloudWatch Logs Insights query that selects the number of unique customers for orders with order quantity equal to 0 and groups the results in 1-day periods. Add the CloudWatch Logs Insights query to a CloudWatch dashboard.

B. Use Amazon Athena to query AWS CloudTrail API logs for API calls. Implement an Athena query that selects the number of unique customers for orders with order quantity equal to 0 and groups the results in 1-day periods. Add the Athena query to an Amazon CloudWatch dashboard.

C. Configure the Lambda function to send events to Amazon EventBridge. Create an EventBridge rule that groups the number of unique customers for orders with order quantity equal to 0 in 1-day periods. Add a CloudWatch dashboard as the target of the rule.

D. Turn on custom Amazon CloudWatch metrics for the DynamoDB stream of the DynamoDB table. Create a CloudWatch alarm that groups the number of unique customers for orders with order quantity equal to 0 in 1-day periods. Add the CloudWatch alarm to a CloudWatch dashboard.

A company is using AWS Elastic Beanstalk to manage web applications that are running on Amazon EC2 instances. A developer needs to make configuration changes. The developer must deploy the changes to new instances only.

Which types of deployment can the developer use to meet this requirement? (Choose two.)

A. All at once

B. Immutable

C. Rolling

D. Blue/green

E. Rolling with additional batch

An application that runs on AWS receives messages from an Amazon Simple Queue Service (Amazon SQS) queue and processes the messages in batches. The application sends the data to another SQS queue to be consumed by another

legacy application. The legacy system can take up to 5 minutes to process some transaction data.

A developer wants to ensure that there are no out-of-order updates in the legacy system.

The developer cannot alter the behavior of the legacy system.

Which solution will meet these requirements?

A. Use an SQS FIFO queue. Configure the visibility timeout value.

B. Use an SQS standard queue with a SendMessageBatchRequestEntry data type. Configure the DelaySeconds values.

C. Use an SQS standard queue with a SendMessageBatchRequestEntry data type. Configure the visibility timeout value.

D. Use an SQS FIFO queue. Configure the DelaySeconds value.

A company has an AWS Lambda function that processes incoming requests from an Amazon API Gateway API. The API calls the Lambda function by using a Lambda alias. A developer updated the Lambda function code to handle more details related to the incoming requests. The developer wants to deploy the new Lambda function for more testing by other developers with no impact to customers that use the API.

Which solution will meet these requirements with the LEAST operational overhead?

A. Create a new version of the Lambda function. Create a new stage on API Gateway with integration to the new Lambda version. Use the new API Gateway stage to test the Lambda function.

B. Update the existing Lambda alias used by API Gateway to a weighted alias. Add the new Lambda version as an additional Lambda function with a weight of 10%. Use the existing API Gateway stage for testing.

C. Create a new version of the Lambda function. Create and deploy a second Lambda function to filter incoming requests from API Gateway. If the filtering Lambda function detects a test request, the filtering Lambda function will invoke the new Lambda version of the code. For other requests, the filtering Lambda function will invoke the old Lambda version. Update the API Gateway API to use the filtering Lambda function.

D. Create a new version of the Lambda function. Create a new API Gateway API for testing purposes. Update the integration of the new API with the new Lambda version. Use the new API for testing.

A developer maintains a critical business application that uses Amazon DynamoDB as the primary data store. The DynamoDB table contains millions of documents and receives 30-60 requests each minute. The developer needs to perform processing in near-real time on the documents when they are added or updated in the DynamoDB table.

How can the developer implement this feature with the LEAST amount of change to the existing application code?

A. Set up a cron job on an Amazon EC2 instance. Run a script every hour to query the table for changes and process the documents.

B. Enable a DynamoDB stream on the table. Invoke an AWS Lambda function to process the documents.

C. Update the application to send a PutEvents request to Amazon EventBridge. Create an EventBridge rule to invoke an AWS Lambda function to process the documents.

D. Update the application to synchronously process the documents directly after the DynamoDB write.

A developer is working on a web application that uses Amazon DynamoDB as its data store. The application has two DynamoDB tables: one table that is named artists and one table that is named songs. The artists table has artistName as the partition key. The songs table has songName as the partition key and artistName as the sort key.

The table usage patterns include the retrieval of multiple songs and artists in a single database operation from the webpage. The developer needs a way to retrieve this information with minimal network traffic and optimal application performance.

Which solution will meet these requirements?

A. Perform a BatchGetltem operation that returns items from the two tables. Use the list of songName/artistName keys for the songs table and the list of artistName key for the artists table.

B. Create a local secondary index (LSI) on the songs table that uses artistName as the partition key. Perform a query operation for each artistName on the songs table that filters by the list of songName. Perform a query operation for each artistName on the artists table.

C. Perform a BatchGetitem operation on the songs table that uses the songName/artistName keys. Perform a BatchGetltem operation on the artists table that uses artistName as the key.

D. Perform a Scan operation on each table that filters by the list of songName/artistName for the songs table and the list of artistName in the artists table.