Free Practice Questions for Amazon Web Services DVA-C02 Exam

Problem:Large bundle size increases Lambda deployment time.

Lambda Layers:Layers let you package dependencies separately from your function code. This optimizes the deployment package, making updates faster.

Modularization:Breaking down dependencies into layers improves code organization and reusability.

Amazon CloudWatch is the service that collects and stores logs from AWS Lambda functions. The developer can use CloudWatch Logs Insights to query and analyze the logs for errors and metrics. Option A is not correct because Amazon S3 is a storage service that does not store Lambda function logs. Option B is not correct because AWS CloudTrail is a service that records API calls and events for AWS services, not Lambda function logs. Option D is not correct because Amazon DynamoDB is a database service that does not store Lambda function logs.

AWS Secrets Manager is a service that helps securely store, rotate, and manage secrets such as API keys, passwords, and tokens. The developer can store the API credentials in AWS Secrets Manager and retrieve them at runtime by using the AWS SDK. This solution will meet the requirements of security, code management, and performance. Storing the API credentials in a local code variable or an S3 object is not secure, as it exposes the credentials to unauthorized access or leakage. Storing the API credentials in a DynamoDB table is also not secure, as it requires additional encryption and access control measures. Moreover, retrieving the credentials from S3 or DynamoDB may affect application performance due to network latency.

Requirement Summary:

DynamoDB table Orders

Partition key: OrderID

No sort key

100,000+ records

Need toefficiently retrieveall records where:

OrderSource = "MobileApp"

Mustoptimize for user experience(i.e., performance)

Evaluate Options:

Option A: Scan with FilterExpression

❌Inefficientfor large tables

AScanreadsevery itemin the table and then applies a filter condition.

This isslow, expensive, andnot scalableas the dataset grows.

Option B: Create a Local Secondary Index (LSI) with OrderSource

❌Invalid: LSIs require thesame partition key(OrderID) as the base table.

Since OrderSource is not part of the primary key, and we want to querybased on it, LSI won’t help.

Option C: Create a GSI with OrderSource as the sort key

❌Misuse of sort key: Querying bysort key alone is not allowedin DynamoDB.

Youmust specify a partition keyin a Query.

This design is not valid for the use case.

Option D: Create a GSI with OrderSource as the partition key

✅✅BEST CHOICE: With a GSI on OrderSource, you canquery efficientlyfor all items where OrderSource = "MobileApp".

DynamoDB GSIs allow analternative access patternfor queries not supported by the base table schema.

GSI Design:https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html

Querying a GSI:https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html

Scan vs Query:https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-query-scan.html

Step-by-Step Breakdown:

Requirement Summary:

Get notified when EC2CPU Utilization > 80%

Option A: CloudWatch Alarm with SNS

✅Correct and standard AWS practice

CloudWatch automatically collectsEC2 metrics, including CPUUtilization.

You can set aCloudWatch Alarmwith a threshold (80% in this case).

Then,trigger an SNS notificationto email, SMS, Lambda, etc.

Option B: AWS CloudTrail alarm

❌Incorrect: CloudTrail logsAPI activity, not performance metrics.

It doesn’t track metrics like CPU utilization.

Option C: Cron job on EC2 running --describe-instance-information

❌Incorrect: This doesn’t give CPU usage.

Also inefficient, and polling is bad practice when CloudWatch already monitors this natively.

Option D: Lambda function querying CloudTrail for CPU usage

❌Incorrect and conceptually flawed.

CloudTrail does not store performance metrics; CloudWatch does.

CloudWatch Alarms for EC2:https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/AlarmThatSendsEmail.html

EC2 Metrics in CloudWatch:https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/viewing_metrics_with_cloudwatch.html

Amazon SNS Notification Setup:https://docs.aws.amazon.com/sns/latest/dg/sns-email-notifications.html

Comprehensive Detailed Step by Step Explanation with All AWS Developer References:

To redact PII from S3 objects before they are accessed by the analytics service, the most efficient solution is to useS3 Object Lambda. S3 Object Lambda allows you to add your own code (Lambda function) to process and transform data when it is retrieved from Amazon S3. You can attach a Lambda function to an S3 Object Lambda Access Point, which in this case would run a redaction API to remove PII from the reports.

Operational Efficiency: S3 Object Lambda handles data processing on the fly, without requiring the data to be permanently transformed or moved to another service (like Amazon Redshift).

Alternatives:

Option A: Loading the data into Amazon Redshift would require refactoring the analytics service and maintaining an additional data pipeline, increasing complexity.

Option C: Using AWS KMS for encryption protects data at rest and in transit, but it does not address PII redaction.

Option D: SNS is a messaging service and does not support direct data transformation.

Pseudo Parameters: CloudFormation provides pseudo parameters that reference runtime context, including the current AWS Region.

Operational Efficiency: The AWS::Region pseudo parameter offers the most direct and self-contained way to obtain the Region dynamically within the template.

DynamoDB distributes throughput across partitions based on the hash key. Ahot partition(caused by high usage of a specific hash key) can result in a ProvisionedThroughputExceededException, even if overall usage is below the provisioned capacity.

Why Option B is Correct:

Partition-Level Limits: Each partition has a limit of 3,000 read capacity units or 1,000 write capacity units per second.

Hot Partition: Excessive use of a single hash key can overwhelm its partition.

Why Not Other Options:

Option A: DynamoDB storage size does not affect throughput.

Option C: Provisioned scaling operations are unrelated to throughput errors.

Option D: Sort keys do not impact partition-level throughput.