Question 1

A company is using an AWS Lambda function to process records from an Amazon Kinesis data stream. The company recently observed slow processing of the records. A developer notices that the iterator age metric for the function is increasing and that the Lambda run duration is constantly above normal. Which actions should the developer take to increase the processing speed? (Choose two.)

Accepted Answer

Increasing the number of shards of the Kinesis data stream will distribute the load across more shards, reducing the number of records that each Lambda function instance needs to process. Increasing the memory that is allocated to the Lambda function will allow it to handle more records at once, reducing the processing time.

Question 2

A developer is writing a new AWS Serverless Application Model (AWS SAM) template with a new AWS Lambda function. The Lambda function runs complex code. The developer wants to test the Lambda function with more CPU power. What should the developer do to meet this requirement?

Accepted Answer

Increasing the memory allocated to an AWS Lambda function also increases the available CPU power, as CPU allocation is proportional to the memory configured.

Question 3

A developer is building a new application that uses an Amazon DynamoDB table. The specification states that all items that are older than 48 hours must be removed. Which solution will meet this requirement?

Accepted Answer

DynamoDB TTL (Time to Live) requires a numeric attribute that represents the expiration time in epoch time format. By setting this attribute to the current timestamp plus 48 hours, items will automatically be removed after 48 hours.

Question 4

A developer is creating a serverless ecommerce application that is based on AWS Lambda. An asynchronous workflow manages the checkout process and must orchestrate different Lambda functions. The workflow runs one function for each item in the shopping cart. The developer is using AWS Step Functions to orchestrate the process. The checkout process is running the Lambda functions serially, and the developer needs to improve the performance of the process. What should the developer do to meet these requirements?

Accepted Answer

Using a Map state in AWS Step Functions allows the developer to iterate over all items in the cart concurrently, improving the performance by processing each item in parallel rather than serially.

Question 5

A developer wants to secure sensitive configuration data such as passwords, database strings, and application license codes. Access to this sensitive information must be tracked for future audit purposes. Where should the sensitive information be stored, adhering to security best practices and operational requirements?

Accepted Answer

The Amazon EC2 Systems Manager Parameter Store is designed for storing configuration data and secrets securely. It provides encryption, access control via IAM, and audit logging, which aligns with the requirement to track access for audit purposes.

Question 6

A company is adding stored value (or gift card) capability to its highly popular casual gaming website. Users need to be able to trade this value for other users' items on the platform. This would require both users' records be updated as a single transaction, or both users' records to be completely rolled back. Which AWS database options can provide the transactional capability required for this new feature? (Choose two.)

Accepted Answer

The answer of A company is adding stored value (or...

Question 7

A company processes incoming documents from an Amazon S3 bucket. Users upload documents to an S3 bucket using a web user interface. Upon receiving files in S3, an AWS Lambda function is invoked to process the files, but the Lambda function times out intermittently. If the Lambda function is configured with the default settings, what will happen to the S3 event when there is a timeout exception?

Accepted Answer

The answer of A company processes incoming documents from an...

Question 8

A developer has built an application using Amazon Cognito for authentication and authorization. After a user is successfully logged in to the application, the application creates a user record in an Amazon DynamoDB table. What is the correct flow to authenticate the user and create a record in the DynamoDB table?

Accepted Answer

The answer of A developer has built an application using...

Question 9

A company has an Amazon S3 bucket containing premier content that it intends to make available to only paid subscribers of its website. The S3 bucket currently has default permissions of all objects being private to prevent inadvertent exposure of the premier content to non-paying website visitors. How can the company limit the ability to download a premier content file in the S3 bucket to paid subscribers only?

Accepted Answer

Generating a pre-signed URL allows temporary access to a specific S3 object, which can be provided to paid subscribers, ensuring that only they can download the content.

Question 10

Which of the following are good use cases for how Amazon ElastiCache can help an application? (Choose two.)

Accepted Answer

Amazon ElastiCache is designed to improve the performance of applications by providing fast in-memory data storage, which is particularly beneficial for read-heavy workloads (C) and compute-intensive applications (E) that require quick data access.

Question 11

A developer is working on an ecommerce website. The developer wants to review server logs without logging in to each of the application servers individually. The website runs on multiple Amazon EC2 instances, is written in Python, and needs to be highly available. How can the developer update the application to meet these requirements with MINIMUM changes?

Accepted Answer

Installing the unified Amazon CloudWatch agent on the EC2 instances allows the developer to push logs to CloudWatch with minimal changes to the existing setup, enabling centralized log review without logging into each server.

Question 12

A developer is adding a feature to a client-side application so that users can upload videos to an Amazon S3 bucket. What is the MOST secure way to give the application the ability to write files to the S3 bucket?

Accepted Answer

The answer of A developer is adding a feature to...

Question 13

A company maintains an application that uses an Amazon RDS DB instance for its database. A developer needs to implement encryption at rest for the database. Which combination of steps should the developer take to meet this requirement? (Choose two.)

Accepted Answer

To implement encryption at rest for an existing RDS DB instance, you need to take a snapshot of the instance, create an encrypted copy of that snapshot, and then restore the DB instance from the encrypted snapshot.

Question 14

A developer added a new feature to an application running on an Amazon EC2 instance that uses Amazon SQS. After deployment, the developer noticed a significant increase in Amazon SQS costs. When monitoring the Amazon SQS metrics on Amazon CloudWatch, the developer found that on average one message per minute is posted on this queue. What can be done to reduce Amazon SQS costs for this application?

Accepted Answer

Increasing the Amazon SQS queue polling timeout can reduce the number of empty receives, which in turn can lower the costs associated with polling the queue.

Question 15

A microservices application is deployed across multiple containers in Amazon Elastic Container Service (Amazon ECS). To improve performance, a developer wants to capture trace information between the microservices and visualize the microservices architecture. Which solution will meet these requirements?

Accepted Answer

The answer of A microservices application is deployed across multiple...

Question 16

A developer is building an AWS Lambda function that will dynamically generate and send a weekly newsletter to 100,000 users. This newsletter contains both static text and images. The developer needs a fast and highly scalable place to store the images that will be hyperlinked in the newsletter. Where should the developer store these images?

Accepted Answer

The answer of A developer is building an AWS Lambda...

Question 17

A company has an application that runs on AWS Lambda@Edge. The application serves content that varies based on the device that the viewer is using. Information about the number of hits by device type is written to logs that are stored in a log group in Amazon CloudWatch Logs. The company needs to publish an Amazon CloudWatch custom metric for each device type. Which approach will meet these requirements?

Accepted Answer

The answer of A company has an application that runs...

Question 18

A developer is troubleshooting the permissions of an application that needs to make changes to an Amazon RDS database. The developer has access to the IAM role that the application is using. Which command structure should the developer use to test the role permissions?

Accepted Answer

The `aws sts assume-role` command allows the developer to assume the IAM role and test the permissions associated with it, which is necessary for troubleshooting access issues with the RDS database.

Question 19

A developer is troubleshooting connectivity issues between an AWS Lambda function and an Amazon EC2 instance that runs Amazon Linux 2. The Lambda function and the EC2 instance cannot communicate with each other even though the Lambda function is configured to access resources in the EC2 instance's subnet. How can the developer inspect the network traffic between the Lambda function and the EC2 instance?

Accepted Answer

VPC flow logs can be used to inspect network traffic between the Lambda function and the EC2 instance.

Question 20

An AWS Lambda function requires read access to an Amazon S3 bucket and requires read/write access to an Amazon DynamoDB table. The correct IAM policy already exists. What is the MOST secure way to grant the Lambda function access to the S3 bucket and the DynamoDB table?

Accepted Answer

Creating an IAM role for the Lambda function and attaching the existing IAM policy to the role is the most secure way. This allows the Lambda function to assume the role and gain the necessary permissions without exposing credentials.

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