DVA-C02 Development with AWS Services Practice Test 14 — 15 Questions

Question 1

Refer to the exhibit. An IAM policy is attached to an IAM user. The user tries to upload an object to the S3 bucket 'example-bucket' from an IP address 198.51.100.5. What will happen?

Accepted Answer

The request is denied because the source IP does not match the condition.. The policy allows s3:PutObject only if the source IP is within 192.0.2.0/24. The user's IP 198.51.100.5 is not in that range, so the request is denied. Option A is correct. Option B is incorrect because the condition is not met. Option C is incorrect because the policy does not enable public access. Option D is incorrect because the user is not root.

Answer

The request is allowed because the user is an IAM user.

Answer

The request is allowed because the action s3:PutObject is allowed.

Answer

The request is denied because the bucket policy is missing.

Question 2

Refer to the exhibit. A developer runs the AWS CLI command to invoke a Lambda function. The command succeeds, but the function returns an error. The developer wants to see the error message and logs from the function execution. What should the developer add to the command?

Accepted Answer

--log-type Tail. The --log-type Tail option returns the last 4 KB of log data. Option B is correct. Option A is incorrect because --invocation-type Event is for async invocation. Option C is incorrect because --client-context is for passing context. Option D is incorrect because --qualifier is for version/alias.

Answer

--client-context string

Answer

--qualifier alias

Answer

--invocation-type Event

Question 3

Refer to the exhibit. An IAM policy statement is attached to an AWS Lambda function's execution role. The function needs to invoke another Lambda function named 'my-function'. However, the invocation fails with an access denied error. What is the most likely cause?

Accepted Answer

The policy is attached to the wrong IAM role.. The policy allows lambda:InvokeFunction on the specific function ARN. Option B is correct because the resource ARN includes the function name, so it should work. Option A is incorrect because the ARN is correct. Option C is incorrect because the action is allowed. Option D is incorrect because the error is access denied, not a timeout.

Answer

The action should be 'lambda:*' to allow all Lambda actions.

Answer

The Lambda function has a timeout set too low.

Answer

The resource ARN is missing the function name.

Question 4

A developer wants to deploy a containerized application to Amazon ECS using Fargate. The application requires persistent storage that can be shared across multiple containers in the same task. Which storage option should the developer use?

Accepted Answer

Amazon EFS file system. Option B is correct because EFS can be mounted as a volume in Fargate tasks and shared among containers. Option A (EBS) is not supported in Fargate. Option C (S3) is object storage, not a file system. Option D (Instance store) is ephemeral and not available in Fargate.

Answer

Amazon EC2 instance store

Answer

Amazon S3 bucket

Answer

Amazon EBS volume

Question 5

A company runs a critical application on AWS Lambda that processes real-time data from Kinesis Data Streams. The function is idempotent, but occasionally duplicate records are processed due to retries. The company wants to ensure exactly-once processing. Which approach should the developer implement?

Accepted Answer

Use a DynamoDB table to store processed record IDs and perform deduplication in the Lambda function.. Option C is correct because using a DynamoDB table to track record IDs allows deduplication. Option A is incorrect because Lambda does not provide built-in deduplication. Option B is incorrect because SQS FIFO does not integrate with Kinesis directly. Option D is incorrect because reducing batch size does not prevent duplicates from retries.

Answer

Use an SQS FIFO queue between Kinesis and Lambda.

Answer

Enable Lambda reserved concurrency to limit retries.

Answer

Reduce the batch size in the event source mapping.

Question 6

A developer is using Amazon API Gateway to create a REST API. The API must support CORS (Cross-Origin Resource Sharing) to allow requests from a web application hosted on a different domain. What must the developer do to enable CORS?

Accepted Answer

Enable CORS in the API Gateway settings and configure the required headers.. Option B is correct because API Gateway can enable CORS by adding the appropriate headers. Option A is incorrect because CORS is not automatically enabled. Option C is incorrect because Lambda does not handle CORS headers for API Gateway. Option D is incorrect because CloudFront is not required.

Answer

Use Amazon CloudFront to proxy the API and add CORS headers.

Answer

Nothing; API Gateway automatically handles CORS.

Answer

Add CORS headers in the Lambda function code.

Question 7

A developer is building a serverless application using AWS Lambda and Amazon DynamoDB. The application experiences occasional throttling on DynamoDB writes. The developer wants to implement a retry mechanism with exponential backoff. Which THREE steps should the developer take?

Accepted Answer

Configure a dead-letter queue (DLQ) for the Lambda function to capture failed events.. Option A, B, and D are correct. The AWS SDK automatically retries with exponential backoff (A). The developer can also implement custom retry logic (B). DLQ helps capture failed events (D). Option C (reserved capacity) does not implement retry. Option E (SQS) is not needed for this scenario.

Answer

Use Amazon SQS to buffer write requests to DynamoDB.

Answer

Increase the DynamoDB table's provisioned write capacity.

Question 8

Refer to the exhibit. A developer invokes an AWS Lambda function and receives this error. The function is configured with a 3-second timeout. The developer needs to process data that sometimes takes up to 10 seconds. What should the developer do?

Accepted Answer

Increase the Lambda function timeout to 10 seconds.. Option D is correct because increasing the timeout to 10 seconds allows the function to complete. Option A is incorrect because increasing memory does not directly affect timeout. Option B is incorrect because async invocation does not change timeout. Option C is incorrect because reserved concurrency does not affect timeout.

Answer

Change the invocation type to Event (async).

Answer

Increase the memory allocation for the Lambda function.

Answer

Set reserved concurrency to 1.

Question 9

A company uses AWS CodeBuild to build and test code. The buildspec.yml includes a pre-build phase that downloads dependencies from a private repository. The developer wants to securely store the credentials for the private repository. Which AWS service should the developer use to store these credentials and reference them in the buildspec?

Accepted Answer

Store the credentials in AWS Systems Manager Parameter Store and reference them in the buildspec.. Option B is correct because AWS Systems Manager Parameter Store can securely store credentials and be referenced in buildspec using parameter-store syntax. Option A is incorrect because environment variables in buildspec are not secure. Option C is incorrect because Secrets Manager is for secrets, not directly referenced in buildspec. Option D is incorrect because S3 is not secure for credentials.

Answer

Store the credentials in an S3 bucket with server-side encryption.

Answer

Store the credentials in AWS Secrets Manager and use the AWS CLI in the build phase to retrieve them.

Answer

Store the credentials in the buildspec.yml file as environment variables.

Question 10

A company is building a serverless application using AWS Lambda and Amazon DynamoDB. The Lambda function processes user uploads from Amazon S3 and stores metadata in DynamoDB. The function is experiencing high latency during peak hours. Which action would MOST improve the performance without increasing the function timeout?

Accepted Answer

Increase the DynamoDB table's provisioned read and write capacity.. Option D is correct because increasing DynamoDB provisioned read/write capacity reduces throttling and latency. Option A is wrong because Lambda reserved concurrency limits throughput. Option B is wrong because DynamoDB Accelerator (DAX) is for read-heavy workloads, but the function writes metadata. Option C is wrong because moving to a VPC adds network latency.

Answer

Increase the Lambda reserved concurrency.

Answer

Move the Lambda function into a VPC with a DynamoDB VPC endpoint.

Answer

Enable DynamoDB Accelerator (DAX) for the table.

Question 11

A developer needs to store temporary session data for a web application running on Amazon EC2 behind an Application Load Balancer. The data must be accessible across multiple EC2 instances. Which AWS service should the developer use?

Accepted Answer

Amazon ElastiCache. Option C is correct because ElastiCache (Redis or Memcached) provides a low-latency, shared cache for session data. Option A is wrong because S3 is object storage with higher latency. Option B is wrong because DynamoDB is a NoSQL database, but session data is temporary and better suited for caching. Option D is wrong because EBS volumes cannot be shared across instances.

Answer

Amazon EBS

Answer

Amazon DynamoDB

Answer

Amazon S3

Question 12

A developer is using AWS CodePipeline to deploy a microservices application to Amazon ECS using the 'Rolling update' deployment type. The pipeline includes a source stage (CodeCommit), build stage (CodeBuild), and deploy stage (CodeDeploy to ECS). After a recent commit, the build stage succeeds, but the deploy stage fails with 'The service has reached the maximum number of running tasks.' What is the MOST likely cause?

Accepted Answer

The ECS service is configured with auto scaling and has reached the maximum task count.. Option A is correct because ECS service auto scaling can set a maximum number of tasks; if the desired count is already at max, the deployment cannot add new tasks. Option B is wrong because deployment type does not affect task count limits. Option C is wrong because ECS service quota is a hard limit, but the error specifically mentions 'maximum number of running tasks' which aligns with auto scaling settings. Option D is wrong because a misconfigured task definition would cause task start failures, not a max task count error.

Answer

The task definition is misconfigured and the task fails to start.

Answer

The ECS service has reached the AWS account service quota for Fargate tasks.

Answer

The CodeDeploy deployment configuration uses a 'canary' instead of 'rolling' update.

Question 13

A company runs a containerized web application on Amazon ECS using Fargate. The application needs to store files in Amazon S3. The developer wants to follow the principle of least privilege for the ECS task IAM role. Which IAM policy should be attached to the task role?

Accepted Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:PutObject","Resource":"arn:aws:s3:::example-bucket/*"}]}. Option B is correct because the policy grants only the necessary S3 actions (PutObject) on the specific bucket. Option A is wrong because it grants all S3 actions. Option C is wrong because it grants s3:* which is too broad. Option D is wrong because it grants read-only access, not write.

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:*","Resource":"*"}]}

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:*","Resource":"arn:aws:s3:::example-bucket/*"}]}

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:GetObject","s3:PutObject"],"Resource":"arn:aws:s3:::example-bucket/*"}]}

Question 14

A developer is writing an AWS Lambda function that processes messages from an Amazon SQS queue. The function should process each message at least once, but duplicates are acceptable. The function is triggered by a Lambda event source mapping. If the function returns an error, what happens to the message?

Accepted Answer

The message remains in the queue and becomes visible after the visibility timeout expires.. Option B is correct because with Lambda event source mapping, if the function fails, the message is not deleted from the queue and becomes visible again after the visibility timeout. Option A is wrong because DLQ is not automatically configured. Option C is wrong because Lambda does not automatically retry with a delay; the SQS visibility timeout controls retry. Option D is wrong because the message is not deleted; it remains in the queue.

Answer

The message is sent to a dead-letter queue (DLQ).

Answer

The message is deleted from the queue to prevent duplicate processing.

Answer

Lambda automatically retries the function with a 1-minute delay.

Question 15

A developer is using AWS Step Functions to orchestrate a workflow that includes a Lambda function for data transformation. The Lambda function occasionally times out after 15 seconds. The Step Function execution fails with a 'States.Timeout' error. The developer wants to retry the Lambda task up to 3 times with exponential backoff. Which configuration should the developer add to the state definition in the Amazon States Language (ASL)?

Accepted Answer

"Retry": [ { "ErrorEquals": ["States.Timeout"], "IntervalSeconds": 1, "BackoffRate": 2, "MaxAttempts": 3 } ]. Option C is correct because it defines a Retry with a 1-second interval, backoff rate of 2, and max attempts of 3. Option A is wrong because it uses 'ErrorEquals' with 'Lambda.ServiceException' which is not the timeout error; the error is 'States.Timeout'. Option B is wrong because it has 'MaxAttempts' as 5, not 3. Option D is wrong because it has only 2 max attempts.

Answer

"Retry": [ { "ErrorEquals": ["States.Timeout"], "IntervalSeconds": 2, "BackoffRate": 3, "MaxAttempts": 5 } ]

Answer

"Retry": [ { "ErrorEquals": ["States.Timeout"], "IntervalSeconds": 1, "BackoffRate": 2, "MaxAttempts": 2 } ]

Answer

"Retry": [ { "ErrorEquals": ["Lambda.ServiceException"], "IntervalSeconds": 1, "BackoffRate": 2, "MaxAttempts": 3 } ]

DVA-C02 Development with AWS Services Practice Test 14 — 15 Questions

Exhibit

DVA-C02 Development with AWS Services Practice Test 14 — 15 Questions

Exhibit