DVA-C02 Development with AWS Services Practice Test 30 — 15 Questions

Question 1

A developer attaches the IAM policy shown to a user. The user attempts to upload an object to example-bucket using the AWS CLI with the command: `aws s3 cp file.txt s3://example-bucket/`. The upload fails. What is the MOST likely reason?

Accepted Answer

The user did not specify server-side encryption in the request.. Option B is correct because the policy requires the `x-amz-server-side-encryption` header to be set to AES256, but the CLI command does not specify SSE. Option A is wrong because the action is allowed. Option C is wrong because the resource allows all objects. Option D is wrong because the bucket policy is not shown.

Answer

The user does not have permission to perform s3:PutObject on the bucket.

Answer

The bucket policy overrides the IAM policy and denies the request.

Answer

The resource ARN does not include the bucket itself.

Question 2

A developer runs the AWS CLI command shown. The Lambda function returns a 200 status code but the output file is null and the response includes FunctionError: Unhandled. What does this indicate?

Accepted Answer

The Lambda function threw an unhandled exception.. Option A is correct because 'Unhandled' means the function threw an exception that was not caught, and the output is null because the function returned an error. Option B is wrong because 200 indicates invocation succeeded. Option C is wrong because no such error. Option D is wrong because the function was invoked.

Answer

The Lambda function timed out.

Answer

The payload was too large for synchronous invocation.

Answer

The Lambda function was not found.

Question 3

A developer creates an AWS CloudFormation stack with the template snippet shown. The stack creation fails with the error: "Bucket with name my-unique-bucket-12345 already exists." What is the MOST likely cause?

Accepted Answer

The bucket name is already taken by another AWS account.. Option C is correct because AWS S3 bucket names must be globally unique, and CloudFormation is trying to create a bucket with a name that already exists. Option A is wrong because the template is valid. Option B is wrong because the name is not taken by the same account. Option D is wrong because IAM permissions would cause a different error.

Answer

The developer does not have permission to create S3 buckets.

Answer

The CloudFormation template has a syntax error.

Answer

The bucket name was used by another stack in the same account.

Question 4

A developer wants to store session state for a web application that runs on multiple EC2 instances behind an Application Load Balancer. Which AWS service should the developer use to store the session state in a centralized, highly available location?

Accepted Answer

Amazon ElastiCache. ElastiCache (Redis or Memcached) is a managed in-memory cache that is commonly used for session state storage across multiple EC2 instances. DynamoDB is also an option but is not listed. S3 is not suitable for session state. RDS is a relational database, not ideal for session state. Lambda is compute, not storage.

Answer

Amazon RDS

Answer

Amazon S3

Answer

AWS Lambda

Question 5

A company is developing a serverless application using AWS Lambda and API Gateway. The application needs to process user uploads to Amazon S3. The Lambda function must be invoked asynchronously after an object is uploaded to an S3 bucket. Which configuration should the developer use to invoke the Lambda function?

Accepted Answer

Configure the S3 bucket to send events to Lambda by adding a Lambda trigger in the S3 bucket properties.. S3 can send event notifications to Lambda when an object is created. The Lambda function must be configured with a resource-based policy allowing S3 to invoke it. S3 event notifications are asynchronous. API Gateway is not needed. CloudWatch Events can monitor but not directly trigger on S3 object creation. S3 batch operations are for large-scale batch jobs.

Answer

Configure the S3 bucket to send events to an Amazon SQS queue and have Lambda poll the queue.

Answer

Configure the S3 bucket to send events to Amazon CloudWatch Events and have CloudWatch invoke Lambda.

Answer

Configure the S3 bucket to send events to an Amazon API Gateway endpoint that triggers the Lambda function.

Question 6

A developer is deploying a microservices application using Amazon ECS with Fargate. The application consists of multiple services that need to communicate with each other over HTTP. The developer wants to ensure that service-to-service communication is encrypted in transit and that the services can discover each other by logical service names instead of IP addresses. Which combination of AWS services should the developer use?

Accepted Answer

AWS App Mesh with AWS Cloud Map. AWS App Mesh provides service mesh capabilities including mTLS for encryption and service discovery using virtual services. AWS Cloud Map is used for service discovery with logical names. Together, they enable encrypted service-to-service communication. Route 53 is for DNS but not mTLS. ELB is for load balancing, not service discovery. Systems Manager is for configuration management, not networking. Direct Connect is a dedicated network connection.

Answer

Elastic Load Balancing with AWS Systems Manager

Answer

Amazon Route 53 with AWS Direct Connect

Answer

AWS Lambda with Amazon API Gateway

Question 7

A developer has written an AWS Lambda function that processes messages from an Amazon SQS queue. The function is configured with a reserved concurrency of 5. The SQS queue has 10,000 messages waiting to be processed. What will happen when the Lambda function is invoked?

Accepted Answer

Lambda will process messages with a maximum of 5 concurrent executions, each processing a batch of messages.. Reserved concurrency limits the maximum number of concurrent invocations to 5. Lambda will poll the SQS queue and process messages up to the reserved concurrency. If the batch size is 10, each invocation processes up to 10 messages, so up to 50 messages can be processed concurrently. The rest remain in the queue. Lambda does not scale beyond reserved concurrency.

Answer

Lambda will automatically increase reserved concurrency to handle the load.

Answer

Lambda will reject the invocation because reserved concurrency is too low.

Answer

Lambda will scale up to 20 concurrent executions to process all messages quickly.

Question 8

A company is using AWS CodePipeline to automate its CI/CD pipeline. The pipeline has a build stage that uses AWS CodeBuild. The developer wants to run unit tests and only proceed to the deploy stage if the tests pass. Which configuration should the developer use to achieve this?

Accepted Answer

Configure the build stage to run tests and fail the build if tests fail; CodePipeline will automatically stop.. CodeBuild can be configured with a buildspec file that defines phases, including a 'post_build' phase for running tests. If the tests fail, CodeBuild returns a non-zero exit code, causing the build to fail. CodePipeline will then stop and not proceed to the deploy stage. The developer can also use a 'test' action in CodePipeline with a test provider like CodeBuild. The other options either don't stop the pipeline or are not automated.

Answer

Configure a manual approval step before the deploy stage.

Answer

Configure Amazon CloudWatch alarms to stop the pipeline if tests fail.

Answer

Configure AWS Lambda to invoke a function that checks test results and manually stops the pipeline.

Question 9

A development team is building a real-time chat application using Amazon API Gateway WebSocket APIs and AWS Lambda. The application needs to maintain a connection to each user and broadcast messages to all connected clients. Which approach should the developer use to scale the application efficiently?

Accepted Answer

Store connection IDs in Amazon DynamoDB and use the API Gateway Management API to send messages to all connections.. API Gateway WebSocket APIs maintain persistent connections. When a client sends a message, API Gateway invokes a Lambda function. To broadcast to all connected clients, the Lambda function needs to call the API Gateway Management API to send messages to each connection. The connection IDs must be stored in a shared data store like DynamoDB. The other options are not suitable: SQS is for message queuing, not broadcasting; SNS is pub/sub but doesn't integrate directly with WebSocket connections; ElastiCache is not designed for this use case.

Answer

Use Amazon ElastiCache to cache connection IDs and have Lambda send messages using the Redis pub/sub feature.

Answer

Use Amazon SNS to publish messages to all connected clients via the WebSocket API.

Answer

Use Amazon SQS to queue messages and have Lambda poll the queue to send messages to all connections.

Question 10

A developer is using AWS SAM to define a serverless application. The application includes an AWS Lambda function that needs to access an Amazon DynamoDB table. The developer wants to grant the Lambda function the minimum required permissions to read and write items in the table. Which resource should the developer use to define the IAM permissions?

Accepted Answer

AWS::Serverless::Function Policies property. In AWS SAM, the AWS::Serverless::Function resource has a Policies property that can be used to attach IAM policies. The developer can use a managed policy like 'AmazonDynamoDBFullAccess' or a custom policy. However, the recommended approach is to use the 'Policies' property with a statement that grants specific DynamoDB actions. AWS::IAM::Role can be used but is not necessary if using SAM. AWS::Lambda::Permission is for resource-based policies, not for Lambda execution role. AWS::DynamoDB::Table defines the table, not permissions.

Answer

AWS::DynamoDB::Table

Answer

AWS::IAM::Role

Answer

AWS::Lambda::Permission

Question 11

A company runs a batch processing job on Amazon ECS using Fargate. The job processes files from an S3 bucket and writes results to another S3 bucket. The job runs once per day and takes about 30 minutes. The company wants to reduce costs by stopping the ECS service when not in use. Which solution should the developer implement?

Accepted Answer

Use AWS Batch with a Fargate launch type and schedule the job with Amazon EventBridge.. AWS Batch is designed for batch computing jobs. It can launch Fargate tasks, run the job, and then stop the resources automatically. The developer can define a job queue and job definition, and schedule the job with Amazon EventBridge (CloudWatch Events). AWS Step Functions can orchestrate but is more complex. ECS Scheduled Tasks can also work, but AWS Batch is purpose-built for this and handles retries, dependencies, and cost optimization better. The other options are not appropriate: EC2 Auto Scaling scales EC2 instances, not Fargate tasks; Lambda has a 15-minute timeout; ECS Service Auto Scaling keeps desired count at least 1, not 0.

Answer

Use an AWS Lambda function to run the job and configure a scheduled event in Amazon EventBridge.

Answer

Use Amazon ECS Service Auto Scaling to scale the service down to zero tasks when not in use.

Answer

Use an Amazon EC2 Auto Scaling group to launch an instance, run the job, and then terminate.

Question 12

A developer is deploying a web application on Amazon EKS. The application needs to read configuration data from an Amazon S3 bucket at startup. The developer wants to ensure that the configuration is securely accessed without embedding AWS credentials in the application code. Which solution should the developer use?

Accepted Answer

Use IAM roles for service accounts (IRSA) to assign an IAM role to the pod.. IAM roles for service accounts (IRSA) allow Kubernetes pods to assume IAM roles. The developer can create an IAM role with an S3 read policy and associate it with a Kubernetes service account. The pod then uses that service account to access S3. This avoids hardcoded credentials. The other options either expose credentials or are not best practice: AWS Secrets Manager stores secrets but not directly for S3 access; environment variables in a ConfigMap can contain credentials but that is insecure; IAM instance profile is for EC2 instances, not for EKS pods directly (though there are workarounds, IRSA is the recommended approach).

Answer

Store the AWS credentials in AWS Secrets Manager and retrieve them at startup.

Answer

Assign an IAM instance profile to the EC2 instances running the EKS nodes.

Answer

Embed the AWS access key and secret key in a Kubernetes ConfigMap.

Question 13

Which TWO AWS services can be used to store and retrieve application configuration data in a serverless application? (Choose two.)

Accepted Answer

AWS AppConfig. AWS AppConfig is designed for application configuration. Amazon DynamoDB is a NoSQL database that can store configuration data. AWS Systems Manager Parameter Store also stores configuration, but it is not listed as an option (it's a valid service but not in the list). AWS CloudFormation is for infrastructure provisioning. Amazon S3 is object storage, not optimized for configuration. AWS Secrets Manager is for secrets, not general configuration.

Answer

Amazon S3

Answer

AWS CloudFormation

Answer

AWS Secrets Manager

Question 14

Which THREE AWS services are commonly used together to build a serverless event-driven architecture that processes real-time streaming data? (Choose three.)

Accepted Answer

Amazon Kinesis Data Streams. Amazon Kinesis Data Streams ingests real-time data. AWS Lambda processes the data. Amazon DynamoDB stores the processed data. Amazon SQS is for message queues, not real-time streaming. Amazon Redshift is a data warehouse, not for real-time streaming. AWS Step Functions orchestrates workflows but is not typically part of a basic streaming pipeline.

Answer

Amazon SQS

Answer

Amazon Redshift

Question 15

Which TWO AWS services can be used to deploy and manage containerized applications? (Choose two.)

Accepted Answer

Amazon ECS. Amazon ECS is a container orchestration service. Amazon EKS is a managed Kubernetes service. AWS Lambda is for serverless functions, not containers. Amazon EC2 is for virtual machines, not specifically for containers. Amazon RDS is a managed database service.

Answer

Amazon EC2

Answer

Amazon RDS

Answer

AWS Lambda

DVA-C02 Development with AWS Services Practice Test 30 — 15 Questions

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DVA-C02 Development with AWS Services Practice Test 30 — 15 Questions

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