amazon AWS Certified Developer Associate - DVA-C01 practice test


Question 1

A company runs an e-commerce website that uses Amazon DynamoDB where pricing for items is dynamically updated in
real time. At any given time, multiple updates may occur simultaneously for pricing information on a particular product. This
is causing the original editors changes to be overwritten without a proper review process.
Which DynamoDB write option should be selected to prevent this overwriting?

  • A. Concurrent writes
  • B. Conditional writes
  • C. Atomic writes
  • D. Batch writes
Answer:

B

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Question 2

A developer manages an application that interacts with Amazon RDS. After observing slow performance with read queries,
the developer implements Amazon ElastiCache to update the cache immediately following the primary database update.
What will be the result of this approach to caching?

  • A. Caching will increase the load on the database instance because the cache is updated for every database update.
  • B. Caching will slow performance of the read queries because the cache is updated when the cache cannot find the requested data.
  • C. The cache will become large and expensive because the infrequently requested data is also written to the cache.
  • D. Overhead will be added to the initial response time because the cache is updated only after a cache miss.
Answer:

D

Explanation:
Reference: https://aws.amazon.com/elasticache/faqs/

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Question 3

A developer is debugging an AWS Lambda function behind an Amazon API Gateway. Whenever the API Gateway endpoint
is called, HTTP status code 200 is returned even though AWS Lambda is recording a 4xx error.
What change needs to be made to return a proper error code through the API Gateway?

  • A. Enable CORS in the API Gateway method settings
  • B. Use a Lambda proxy integration to return HTTP codes and headers
  • C. Enable API Gateway error pass-through.
  • D. Return the value in the header x-Amzn-ErrorType.
Answer:

A

Explanation:
Reference: https://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-cors.html

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Question 4

A developer is creating a new application that will be accessed by users through an API created using Amazon API
Gateway. The users need to be authenticated by a third-party Security Assertion Markup Language (SAML) identity provider.
Once authenticated, users will need access to other AWS services, such as Amazon S3 and Amazon DynamoDB.
How can these requirements be met?

  • A. Use an Amazon Cognito user pool with SAML as the resource server.
  • B. Use Amazon Cognito identity pools with a SAML identity provider as one of the authentication providers.
  • C. Use the AWS IAM service to provide the sign-up and sign-in functionality.
  • D. Use Amazon CloudFront signed URLs to connect with the SAML identity provider.
Answer:

A

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Question 5

A Developer wants to insert a record into an Amazon DynamoDB table as soon as a new file is added to an Amazon S3
bucket.
Which set of steps would be necessary to achieve this?

  • A. Create an event with Amazon CloudWatch Events that will monitor the S3 bucket and then insert the records into DynamoDB.
  • B. Configure an S3 event to invoke a Lambda function that inserts records into DynamoDB.
  • C. Create a Lambda function that will poll the S3 bucket and then insert the records into DynamoDB.
  • D. Create a cron job that will run at a scheduled time and insert the records into DynamoDB.
Answer:

B

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Question 6

A Developer is writing an application that runs on Amazon EC2 instances in an Auto Scaling group. The application data is
stored in an Amazon DynamoDB table and records are constantly updated by all instances. An instance sometimes retrieves
old data. The Developer wants to correct this by making sure the reads are strongly consistent.
How can the Developer accomplish this?

  • A. Set ConsistentRead to true when calling GetItem.
  • B. Create a new DynamoDB Accelerator (DAX) table.
  • C. Set Consistency to strong when calling UpdateTable.
  • D. Use the GetShardIterator command.
Answer:

A

Explanation:
Reference: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadConsistency.html

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Question 7

A developer is building an application on Amazon EC2. The developer encountered an Access Denied error on some of the
API calls to AWS services while testing. The developer needs to modify permissions that have been already given to the
instance.
How can these requirements be met with minimal changes and minimum downtime?

  • A. Make a new IAM role with the needed permissions. Stop the instance. Attach the new IAM role to the instance. Start the instance.
  • B. Delete the existing IAM role. Attach a new IAM role with the needed permissions.
  • C. Stop the instance. Update the attached IAM role adding the needed permissions. Start the instance.
  • D. Update the attached IAM role adding the needed permissions.
Answer:

B

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Question 8

A Development team decides to adopt a continuous integration/continuous delivery (CI/CD) process using AWS
CodePipeline and AWS CodeCommit for a new application. However, management wants a person to review and approve
the code before it is deployed to production.
How can the Development team add a manual approver to the CI/CD pipeline?

  • A. Use AWS SES to send an email to approvers when their action is required. Develop a simple application that allows approvers to accept or reject a build. Invoke an AWS Lambda function to advance the pipeline when a build is accepted.
  • B. If approved, add an approved tag when pushing changes to the CodeCommit repository. CodePipeline will proceed to build and deploy approved commits without interruption.
  • C. Add an approval step to CodeCommit. Commits will not be saved until approved.
  • D. Add an approval action to the pipeline. Configure the approval action to publish to an Amazon SNS topic when approval is required. The pipeline execution will stop and wait for an approval.
Answer:

D

Explanation:
Reference: https://docs.aws.amazon.com/codepipeline/latest/userguide/approvals-action-add.html

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Question 9

A company is managing a NoSQL database on-premises to host a critical component of an application, which is starting to
have scaling issues. The company wants to migrate the application to Amazon DynamoDB with the following considerations:
Optimize frequent queries

Reduce read latencies

Plan for frequent queries on certain key attributes of the table

Which solution would help achieve these objectives?

  • A. Create global secondary indexes on keys that are frequently queried. Add the necessary attributes into the indexes.
  • B. Create local secondary indexes on keys that are frequently queried. DynamoDB will fetch needed attributes from the table.
  • C. Create DynamoDB global tables to speed up query responses. Use a scan to fetch data from the table.
  • D. Create an AWS Auto Scaling policy for the DynamoDB table.
Answer:

A

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Question 10

A Developer has an Amazon DynamoDB table that must be in provisioned mode to comply with user requirements. The
application needs to support the following: Average item size: 10 KB

Item reads each second: 10 strongly consistent Item writes each second: 2 transactional


Which read and write capacity cost-effectively meets these requirements?

  • A. Read 10; write 2
  • B. Read 30; write 40
  • C. Use on-demand scaling
  • D. Read 300; write 400
Answer:

B

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