Question 1

A Developer is writing an application that will run on Amazon EC2 instances in an Auto Scaling group. The Developer wants to externalize session state to support the application. Which services will meet these needs? (Choose two.)

Accepted Answer

A)  Amazon DynamoDB 
B)  Amazon Cognito 
C)  Amazon ElastiCache 
D)  Amazon EBS 
E)  Amazon SQS

Question 2

A developer is writing an AWS Lambda function. The developer wants to log key events that occur during the Lambda function and include a unique identifier to associate the events with a specific function invocation. Which of the following will help the developer accomplish this objective?

Accepted Answer

A)  Obtain the request identifier from the Lambda context object. Architect the application to write logs to the console. 
B)  Obtain the request identifier from the Lambda event object. Architect the application to write logs to a file. 
C)  Obtain the request identifier from the Lambda event object. Architect the application to write logs to the console. 
D)  Obtain the request identifier from the Lambda context object. Architect the application to write logs to a file.

Question 3

An application is designed to use Amazon SQS to manage messages from many independent senders. Each sender's messages must be processed in the order they are received. Which SQS feature should be implemented by the Developer?

Accepted Answer

A)  Configure each sender with a unique MessageGroupId Configure each sender with a unique MessageGroupId 
B)  Enable MessageDeduplicationIds on the SQS queue Enable MessageDeduplicationIds on the SQS queue 
C)  Configure each message with unique MessageGroupIds. 
D)  Enable ContentBasedDeduplication on the SQS queue ContentBasedDeduplication

Question 4

A Developer has written a serverless application using multiple AWS services. The business logic is written as a Lambda function which has dependencies on third-party libraries. The Lambda function endpoints will be exposed using Amazon API Gateway. The Lambda function will write the information to Amazon DynamoDB. The Developer is ready to deploy the application but must have the ability to rollback. How can this deployment be automated, based on these requirements?

Accepted Answer

A)  Deploy using Amazon Lambda API operations to create the Lambda function by providing a deployment package. 
B)  Use an AWS CloudFormation template and use CloudFormation syntax to define the Lambda function resource in the template. 
C)  Use syntax conforming to the Serverless Application Model in the AWS CloudFormation template to define the Lambda function resource. 
D)  Create a bash script which uses AWS CLI to package and deploy the application.

Question 5

A company needs a version control system for collaborative software development. Features of the system must include the following: Support for batches of changes across multiple files Parallel branching Version tracking Which AWS service will meet these requirements?

Accepted Answer

A)  AWS CodePipeline 
B)  Amazon S3 
C)  AWS CodeBuild 
D)  AWS CodeCommit

Question 6

A developer works in an environment with multiple AWS accounts that have AWS Lambda functions processing the same 100 KB payloads. The developer wants to centralize the point of origin of the payloads to one account and have all the Lambda functions be invoked whenever the initiating event occurs in the parent account. How can the developer design the workflow in the MOST efficient way, so all the multi-account Lambda functions get invoked when the event occurs?

Accepted Answer

A)  Create a Lambda function in the parent account and use cross-account IAM roles with the AWS Security Token Service (AWS STS) AssumeRole API call to make AWS Lambda invoke the API call to invoke all the cross-account Lambda functions. 
B)  Subscribe all the multi-account Lambda functions to an Amazon SNS topic and make a SNS Publish API call with the payload to the SNS topic. 
C)  Set up an Amazon SQS queue with the queue policy permitting the ReceiveMessage action for multi-account Lambda functions. Then send the payload to the SQS queue using the sqs:SendMessage permission and poll the queue using multi-account Lambda functions. 
D)  Use a worker on an Amazon EC2 instance to poll for the payload event. Invoke all Lambda functions using the Lambda Invoke API after using cross-account IAM roles with the AWS Security Token Service (AWS STS) AssumeRole API call.

Question 7

A Developer is working on an application that tracks hundreds of millions of product reviews in an Amazon DynamoDB table. The records include the data elements shown in the table:  Which field, when used as the partition key, would result in the MOST consistent performance using DynamoDB?

Accepted Answer

A)  starRating 
B)  reviewID 
C)  comment 
D)  productID

Question 8

Which code snippet below returns the URL of a load balanced web site created in CloudFormation with an AWS::ElasticLoadBalancing::LoadBalancer resource name "ElasticLoad Balancer"?

Accepted Answer

A)  "Fn::Join" : ["". [ "http://", {"Fn::GetAtr" : [ "ElasticLoadBalancer","DNSName"]}]] 
B)  "Fn::Join" : ["". [ "http://", {"Fn::GetAtr" : [ "ElasticLoadBalancer","Url"]}]] 
C)  "Fn::Join" : ["". [ "http://", {"Ref" : "ElasticLoadBalancerUrl"}]] 
D)  "Fn::Join" : [".", [ "http://", {"Ref" : "ElasticLoadBalancerDNSName"}]]

Question 9

An organization is using Amazon CloudFront to ensure that its users experience low-latency access to its web application. The organization has identified a need to encrypt all traffic between users and CloudFront, and all traffic between CloudFront and the web application. How can these requirements be met? (Choose two.)

Accepted Answer

A)  Use AWS KMS to encrypt traffic between CloudFront and the web application. 
B)  Set the Origin Protocol Policy to "HTTPS Only". 
C)  Set the Origin's HTTP Port to 443. 
D)  Set the Viewer Protocol Policy to "HTTPS Only" or "Redirect HTTP to HTTPS". 
E)  Enable the CloudFront option Restrict Viewer Access.

Question 10

An e-commerce web application that shares session state on-premises is being migrated to AWS. The application must be fault tolerant, natively highly scalable, and any service interruption should not affect the user experience. What is the best option to store the session state?

Accepted Answer

A)  Store the session state in Amazon ElastiCache 
B)  Store the session state in Amazon CloudFront 
C)  Store the session state in Amazon S3 
D)  Enable session stickiness using elastic load balancers

Question 11

An application is real-time processing millions of events that are received through an API. What service could be used to allow multiple consumers to process the data concurrently and MOST cost-effectively?

Accepted Answer

A)  Amazon SNS with fanout to an SQS queue for each application 
B)  Amazon SNS with fanout to an SQS FIFO (first-in, firtst-out) queue for each application 
C)  Amazon Kinesis Firehouse 
D)  Amazon Kinesis Streams

Question 12

A Developer is investigating an issue whereby certain requests are passing through an Amazon API Gateway endpoint /MyAPI, but the requests do not reach the AWS Lambda function backing /MyAPI. The Developer found that a second Lambda function sometimes runs at maximum concurrency allowed for the given AWS account. How can the Developer address this issue?

Accepted Answer

A)  Manually reduce the concurrent execution limit at the account level 
B)  Add another API Gateway stage for /MyAPI, and shard the requests 
C)  Configure the second Lambda function's concurrency execution limit 
D)  Reduce the throttling limits in the API Gateway /MyAPI endpoint

Question 13

A developer has built a market application that stores pricing data in Amazon DynamoDB with Amazon ElastiCache in front. The prices of items in the market change frequently. Sellers have begun complaining that, after they update the price of an item, the price does not actually change in the product listing. What could be causing this issue?

Accepted Answer

A)  The cache is not being invalidated when the price of the item is changed 
B)  The price of the item is being retrieved using a write-through ElastiCache cluster 
C)  The DynamoDB table was provisioned with insufficient read capacity 
D)  The DynamoDB table was provisioned with insufficient write capacity

Question 14

A developer is setting up Amazon API Gateway for their company's products. The API will be used by registered developers to query and update their environments. The company wants to limit the amount of requests end users can send for both cost and security reasons. Management wants to offer registered developers the option of buying larger packages that allow for more requests. How can the developer accomplish this with the LEAST amount of overhead management?

Accepted Answer

A)  Enable throttling for the API Gateway stage. Set a value for both the rate and burst capacity. If a registered user chooses a larger package, create a stage for them, adjust the values, and share the new URL with them. 
B)  Set up Amazon CloudWatch API logging in API Gateway. Create a filter based on the user and requestTime fields and create an alarm on this filter. Write an AWS Lambda function to analyze the values and requester information, and respond accordingly. Set up the function as the target for the alarm. If a registered user chooses a larger package, update the Lambda code with the values. 
C)  Enable Amazon CloudWatch metrics for the API Gateway stage. Set up CloudWatch alarms based off the Count metric and the ApiName, Method, Resource, and Stage dimensions to alerts when request rates pass the threshold. Set the alarm action to Deny. If a registered user chooses a larger package, create a user-specific alarm and adjust the values. 
D)  Set up a default usage plan, specify values for the rate and burst capacity, and associate it with a stage. If a registered user chooses a larger package, create a custom plan with the appropriate values and associate the plan with the user.

Question 15

A Developer migrated a web application to AWS. As part of the migration, the Developer implemented an automated continuous integration/continuous improvement (CI/CD) process using a blue/green deployment. The deployment provisions new Amazon EC2 instances in an Auto Scaling group behind a new Application Load Balancer. After the migration was completed, the Developer began receiving complaints from users getting booted out of the system. The system also requires users to log in after every new deployment. How can these issues be resolved?

Accepted Answer

A)  Use rolling updates instead of a blue/green deployment 
B)  Externalize the user sessions to Amazon ElastiCache 
C)  Turn on sticky sessions in the Application Load Balancer 
D)  Use multicast to replicate session information

Question 16

The Developer for a retail company must integrate a fraud detection solution into the order processing solution. The fraud detection solution takes between ten and thirty minutes to verify an order. At peak, the web site can receive one hundred orders per minute. What is the most scalable method to add the fraud detection solution to the order processing pipeline?

Accepted Answer

A)  Add all new orders to an Amazon SQS queue. Configure a fleet of 10 EC2 instances spanning multiple AZs with the fraud detection solution installed on them to pull orders from this queue. Update the order with a pass or fails status. 
B)  Add all new orders to an SQS queue. Configure an Auto Scaling group that uses the queue depth metric as its unit of scale to launch a dynamically-sized fleet of EC2 instances spanning multiple AZs with the fraud detection solution installed on them to pull orders from this queue. Update the order with a pass or fails status. 
C)  Add all new orders to an Amazon Kinesis Stream. Subscribe a Lambda function to automatically read batches of records from the Kinesis Stream. The Lambda function includes the fraud detection software and will update the order with a pass or fail status. 
D)  Write all new orders to Amazon DynamoDB. Configure DynamoDB Streams to include all new orders. Subscribe a Lambda function to automatically read batches of records from the Kinesis Stream. The Lambda function includes the fraud detection software and will update the order with a pass or fail status.

Question 17

What item operation allows the retrieval of multiple items from a DynamoDB table in a single API call?

Accepted Answer

A)  GetItem 
B)  BatchGetItem 
C)  GetMultipleItems 
D)  GetItemRange

Question 18

A developer is creating a website that will be hosted from an Amazon S3 bucket. The website must support secure browser connections. Which combination of actions must the developer take to meet this requirement? (Choose two.)

Accepted Answer

A)  Create an Elastic Load Balancer (EL
B) . Configure the ELB to direct traffic to the S3 bucket. 
B)  Create an Amazon CloudFront distribution. Set the S3 bucket as an origin. 
C)  Configure the Elastic Load Balancer with an SSL/TLS certificate. 
D)  Configure the Amazon CloudFront distribution with an SSL/TLS certificate. 
E)  Configure the S3 bucket with an SSL/TLS certificate.

Question 19

A Developer implemented a static website hosted in Amazon S3 that makes web service requests hosted in Amazon API Gateway and AWS Lambda. The site is showing an error that reads: "No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access." What should the Developer do to resolve this issue?

Accepted Answer

A)  Enable cross-origin resource sharing (CORS) on the S3 bucket. 
B)  Enable cross-origin resource sharing (CORS) for the method in API Gateway 
C)  Add the Access-Control-Request-Method header to the request 
D)  Add the Access-Control-Request-Headers header to the request

Question 20

An on-premises legacy application is caching data files locally and writing shared images to local disks. What is necessary to allow for horizontal scaling when migrating the application to AWS?

Accepted Answer

A)  Modify the application to have both shared images and caching data written to Amazon EBS. 
B)  Modify the application to read and write cache data on Amazon S3, and also store shared images on S3. 
C)  Modify the application to use Amazon S3 for serving shared images; cache data can then be written to local disks. 
D)  Modify the application to read and write cache data on Amazon S3, while continuing to write shared images to local disks.

Exam 6: AWS Certified Developer Associate (DVA-C01)