DVA-C02 Development with AWS Services Practice Test 8 — 15 Questions

Question 1

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 (C) is correct because it is a purpose-built feature of AWS Systems Manager for storing, validating, and deploying application configuration data and feature flags to serverless workloads, with built-in versioning, gradual rollouts, and automatic rollback. Amazon DynamoDB (E) is correct because it is a fully managed serverless key-value store that applications can read and write at runtime to persist and retrieve configuration items without provisioning servers. Amazon S3 (A) is not the intended answer here since it is object storage rather than a configuration-management service, even though config files can technically be placed in a bucket. AWS CloudFormation (B) is an infrastructure-as-code provisioning service, not a runtime configuration store. AWS Secrets Manager (D) is designed for storing and rotating secrets such as credentials and API keys, not general application configuration data.

Answer

Amazon S3

Answer

AWS CloudFormation

Answer

AWS Secrets Manager

Question 2

Refer to the exhibit. The IAM policy is attached to an IAM role that is assumed by an AWS Lambda function. The Lambda function needs to read and write objects in the 'my-bucket' S3 bucket, but it should never delete objects. What will happen when the function attempts to delete an object?

Answer

The delete will fail because the Deny statement explicitly denies the delete action.

Answer

The delete will succeed because there is no explicit deny for the specific object.

Answer

The delete will succeed because the Allow statement gives full access.

Answer

The delete will fail because the Allow statement only includes GetObject and PutObject.

Question 3

Refer to the exhibit. A developer creates a CloudFormation stack with the above template. The stack creation fails with the error 'The runtime parameter of nodejs18.x is not supported.' What is the most likely cause?

Accepted Answer

The Handler property is incorrect; it should be 'index.handler' but with the correct filename.. AWS Lambda regularly deprecates older runtimes. Once a runtime reaches the end of its deprecation path (Phase 1), AWS Lambda no longer supports the creation of new functions using that runtime. Attempting to deploy a CloudFormation stack with a deprecated runtime (such as nodejs16.x, which was deprecated in 2024) will result in the error: 'The runtime parameter of nodejs16.x is not supported.' To resolve this, the developer must update the Runtime property to a supported version, such as nodejs18.x or nodejs20.x.

Answer

The ZipFile property cannot contain inline code for Node.js functions.

Answer

The IAM role is missing necessary permissions for CloudWatch Logs.

Answer

The runtime 'nodejs18.x' is not a valid Lambda runtime; use a supported runtime like 'nodejs16.x'.

Question 4

A developer is using AWS CloudFormation to deploy a stack that includes an Amazon RDS DB instance. The developer wants to ensure that the DB instance is not accidentally deleted when the stack is updated. Which property should be set on the DB instance resource?

Accepted Answer

DeletionPolicy: Retain. Setting `DeletionPolicy: Retain` on an Amazon RDS DB instance in a CloudFormation template ensures that when the stack is deleted, the DB instance is preserved and not removed. This property overrides the default behavior where CloudFormation would delete the resource when the stack is deleted, preventing accidental data loss.

Answer

UpdateReplacePolicy: Retain

Answer

DeletionPolicy: Delete

Answer

DependsOn: SomeOtherResource

Question 5

A developer is using Amazon Kinesis Data Streams to ingest real-time events. The application uses the Kinesis Client Library (KCL) to process records. The developer notices that one shard is falling behind while others are processing fine. Which THREE actions can help improve processing of the lagging shard? (Choose THREE.)

Accepted Answer

Use Enhanced Fan-Out to reduce contention.. Option A is correct because Enhanced Fan-Out gives each consumer a dedicated 2 MB/sec read throughput per shard using HTTP/2 push, eliminating the shared 2 MB/sec per-shard read limit and reducing contention that can cause one shard's consumer to lag. Option D is correct because increasing the number of KCL workers (instances) allows the KCL to distribute shard leases across more processing capacity, so a lagging shard can be picked up and processed by an available worker rather than waiting on an overloaded one. Option E is correct because splitting a hot shard via resharding (SplitShard) divides the incoming record traffic across multiple child shards, so the previously lagging shard's load is spread out and can be processed in parallel. Option B is not correct because Kinesis Data Streams does not compress records on the service side and record size is not the cause of a single shard lagging; compression is an application-level choice that does not address per-shard read throughput or worker capacity. Option C is not correct because reducing the number of shards lowers total stream capacity and would worsen, not improve, a lagging shard's processing.

Answer

Decrease the record size by compressing the data.

Answer

Reduce the number of shards in the stream.

Question 6

A developer is deploying a Lambda function that processes messages from an SQS queue. The queue has a batch size of 10. To optimize cost and performance, the developer wants to minimize the number of Lambda invocations while ensuring that all messages are processed within the SQS visibility timeout. Which configuration should the developer use?

Accepted Answer

Set the Lambda function timeout to less than the SQS visibility timeout.. Setting the Lambda function timeout to less than the SQS visibility timeout ensures that the function completes (success or failure) before the message visibility timeout expires. This prevents the message from becoming visible again while the function is still running, which would cause duplicate invocations. If the function fails, the message remains in the queue and becomes visible again after the original visibility timeout, allowing for reprocessing without overlapping executions. This configuration keeps the number of invocations to one per batch for successful processing and avoids unintended duplicates, rather than adding extra retries.

Answer

Increase the SQS visibility timeout to 5 minutes and set Lambda timeout to 5 minutes.

Answer

Configure the Lambda function to process messages asynchronously.

Answer

Set the Lambda reserved concurrency to 1 to limit concurrent executions.

Question 7

A developer is designing a serverless application using AWS Lambda and Amazon S3. The application must process files immediately after they are uploaded to an S3 bucket. Which TWO services can be used to trigger the Lambda function?

Accepted Answer

Amazon SQS. Amazon SQS (option C) is correct because an S3 bucket can publish event notifications directly to an SQS queue, and Lambda natively supports SQS as an event source, polling the queue and invoking the function with batches of messages, which enables near-immediate processing of uploaded files. Amazon SNS (option D) is correct because S3 event notifications can target an SNS topic, and Lambda can be subscribed to that topic so the function is invoked as soon as the upload event is published. Amazon Kinesis Data Streams (A) is not a valid S3 event notification destination and would require additional producers, so it does not directly trigger on uploads. Amazon CloudWatch Events (B) is for scheduled or AWS API/service-state events, not S3 object-created notifications. AWS Lambda S3 event notifications (E) is a distractor: S3 event notifications are a feature of S3 that can invoke Lambda, but it is not a separate AWS service that can be selected as a trigger service in this context.

Answer

Amazon Kinesis Data Streams

Answer

Amazon CloudWatch Events

Answer

AWS Lambda S3 event notifications

Question 8

A developer is configuring an Amazon API Gateway REST API with a Lambda function as the backend. The Lambda function returns a JSON response. The developer wants to enable caching to reduce the number of calls to the Lambda function. Which TWO steps are required to enable caching for a specific stage?

Accepted Answer

Configure cache key parameters in the method request.. To enable caching for a REST API stage in API Gateway, option B (Enable API caching in the stage settings) is required because caching is a stage-level feature that must be turned on in the stage's Cache settings, where you also set the cache capacity (e.g., 0.5 GB to 237 GB) and optionally per-method cache overrides. Option A (Configure cache key parameters in the method request) is also required because API Gateway only caches responses based on the cache key, which is built from method request parameters you explicitly designate (such as query string, path, or header parameters); without defined cache key parameters, the cache cannot distinguish requests and caching will not function as intended. Option C is incorrect because a custom domain name only affects how clients reach the API and has no bearing on caching. Option D is incorrect because API keys and usage plans are for throttling and access control, not for enabling caching. Option E is incorrect because edge-optimized versus regional endpoint type is a deployment/routing choice unrelated to stage caching.

Answer

Attach a custom domain name to the API.

Answer

Create an API key and usage plan.

Answer

Deploy the API to an edge-optimized endpoint.

Question 9

A developer is deploying an application using AWS Elastic Beanstalk. The application requires a relational database. Which THREE components are created by Elastic Beanstalk when you add a database to your environment?

Accepted Answer

A DB subnet group. When you add a database to an Elastic Beanstalk environment, Elastic Beanstalk provisions an Amazon RDS DB instance (B), which is the actual relational database engine (e.g., MySQL, PostgreSQL) attached to the environment. It also creates a DB subnet group (A) so the RDS instance can be placed in the VPC's subnets across Availability Zones. Additionally, a security group for the database (E) is created to control network access between the EC2 instances and the RDS instance. Option C is not correct because the CloudFormation stack is the underlying mechanism Elastic Beanstalk uses to provision resources, not a component created specifically by adding a database. Option D is not correct because DynamoDB is a NoSQL service and is not provisioned by Elastic Beanstalk when adding a relational database.

Answer

An AWS CloudFormation stack

Answer

An Amazon DynamoDB table

Question 10

A developer is troubleshooting a Lambda function that is failing with a 'Task timed out' error. The function is configured with a 3-second timeout. The function makes an HTTP request to an external API that sometimes takes more than 3 seconds to respond. Which THREE actions should the developer take to resolve this issue?

Accepted Answer

Use an asynchronous invocation pattern with a queue to decouple the HTTP request.. Option A is correct because decoupling the slow external HTTP call with an asynchronous invocation pattern and a queue (e.g., SQS) lets the Lambda return quickly while the request is processed separately, avoiding the 3-second timeout on the synchronous path. Option C is correct because the external API sometimes takes longer than 3 seconds, so raising the function timeout to 10 seconds gives the HTTP request enough time to complete before Lambda terminates execution. Option E is correct because implementing retry logic with exponential backoff handles transient failures or slow responses from the external API gracefully, improving reliability without immediately failing the invocation. Option B is not correct because placing the function in a VPC does not reduce latency to an external public API and can even add cold-start/ENI overhead. Option D is not correct because reducing batch size in an event source mapping only affects how many records are read per invocation and does not address a single slow outbound HTTP request timing out.

Answer

Place the Lambda function in a VPC to improve network latency.

Answer

Reduce the batch size in the event source mapping.

Question 11

A developer is building a serverless application using AWS Lambda to process events from Amazon S3. The Lambda function needs to persist data to an Amazon RDS MySQL database. Which of the following is the MOST secure way to pass database credentials to the Lambda function?

Accepted Answer

Store the credentials in AWS Secrets Manager and retrieve them in the Lambda function code.. AWS Secrets Manager provides a secure, auditable, and automated way to store and retrieve database credentials. The Lambda function can assume an IAM role with permissions to access the secret, and retrieve the credentials at runtime using the AWS SDK, avoiding hardcoding or insecure storage. This approach also supports automatic rotation of credentials, enhancing security.

Answer

Store the credentials in an S3 bucket with server-side encryption and read them in the Lambda function.

Answer

Use IAM database authentication for MySQL and assign an IAM role to the Lambda function.

Answer

Hardcode the credentials as environment variables in the Lambda function configuration.

Question 12

A developer is implementing a REST API using Amazon API Gateway and AWS Lambda. The API should return a static response from an Amazon S3 bucket for a specific GET endpoint without invoking a Lambda function. Which API Gateway integration type should be used?

Accepted Answer

AWS. To integrate API Gateway directly with an AWS service like Amazon S3, you use the 'AWS' integration type. This allows API Gateway to securely call the S3 GetObject API using an IAM execution role, enabling access to private S3 buckets without invoking a Lambda function. While 'HTTP_PROXY' can technically forward requests to a public S3 static website endpoint, it is not the standard AWS service integration and does not support secure access to private buckets via IAM.

Answer

MOCK

Answer

HTTP_PROXY

Answer

AWS_PROXY

Question 13

A developer is designing a workflow using AWS Step Functions that includes a task to invoke an AWS Lambda function. The Lambda function sometimes times out due to long-running operations. The developer needs the workflow to wait for the Lambda function to complete asynchronously and retry on failure. Which Step Functions pattern should the developer use?

Accepted Answer

Use a Task state with .waitForTaskToken and have the Lambda function return the token upon completion.. In AWS Step Functions, you can handle transient failures and timeouts in a Task state by using a `Retry` block. By catching `States.Timeout` (which occurs when the task runs longer than the specified `TimeoutSeconds`) or specific Lambda service errors (like `Lambda.SdkClientException`), Step Functions can automatically retry the task according to the defined backoff rate and maximum attempts.

Answer

Use a Task state that directly invokes the Lambda function synchronously.

Answer

Use a Parallel state to run multiple Lambda functions concurrently.

Answer

Use a Choice state to branch based on the Lambda function's output.

Question 14

A developer is designing a microservices architecture using Amazon ECS with Fargate. The services need to communicate with each other. Which TWO options can the developer use for service discovery?

Accepted Answer

AWS Cloud Map. AWS Cloud Map (A) is correct because it is the native service discovery service for AWS, allowing ECS tasks to register and discover each other via DNS names or API calls, and it integrates directly with ECS service discovery. Amazon ECS Service Connect (C) is correct because it is a purpose-built ECS feature that provides service discovery and connectivity between microservices using a built-in proxy, without requiring a load balancer or custom code. AWS Global Accelerator (B) is not a service discovery mechanism; it optimizes global traffic routing to endpoints via anycast IP addresses. Amazon Route 53 private hosted zones (D) can be used for DNS-based discovery but are not a dedicated ECS service discovery option and require manual or custom integration. An Application Load Balancer internal (E) provides load balancing and routing but does not itself provide service discovery for microservices.

Answer

AWS Global Accelerator

Answer

Amazon Route 53 private hosted zones

Answer

Application Load Balancer internal

Question 15

A developer is using AWS CodeBuild to run unit tests as part of a CI/CD pipeline. The developer wants to store the test results for later analysis. Which TWO AWS services can the developer use to store and view the test reports?

Accepted Answer

AWS CodeBuild test reports. Option A (AWS CodeBuild test reports) is correct because CodeBuild natively supports test reporting: when a buildspec contains a reports: section with report-group definitions, CodeBuild parses supported test result formats (JUnit XML, Cucumber JSON, TestNG XML, etc.) and stores them as report groups that can be viewed directly in the CodeBuild console with pass/fail counts and test case details. Option D (Amazon S3) is correct because CodeBuild stores the raw test result artifacts and report data in an S3 bucket, and you can configure the reports: section with a base-directory and file-format so the test output files are uploaded to S3 for later retrieval and analysis. Option B (AWS X-Ray) is not correct because X-Ray is a distributed tracing service for analyzing request paths and latency, not for storing or viewing unit test reports. Option C (Amazon Athena) is not correct because Athena is an interactive query service for data in S3 using SQL, not a test-report storage or viewing service. Option E (Amazon CloudWatch Logs) is not correct because CloudWatch Logs captures build log output streams, not structured test reports with per-test-case results.

Answer

AWS X-Ray

Answer

Amazon Athena

Answer

Amazon CloudWatch Logs