A company has an ecommerce application. To track product reviews, the company's development team uses an Amazon DynamoDB table.
Every record includes the following
• A Review ID a 16-digrt universally unique identifier (UUID)
• A Product ID and User ID 16 digit UUlDs that reference other tables
• A Product Rating on a scale of 1-5
• An optional comment from the user
The table partition key is the Review ID. The most performed query against the table is to find the 10 reviews with the highest rating for a given product.
Which index will provide the FASTEST response for this query"?
Correct Answer:
A
This solution allows the fastest response for the query because it enables the query to use a single partition key value (the Product ID) and a range of sort key values (the Product Rating) to find the matching items. A global secondary index (GSI) is an index that has a partition key and an optional sort key that are different from those on the base table. A GSI can be created at any time and can be queried or scanned independently of the base table. A local secondary index (LSI) is an index that has the same partition key as the base table, but a different sort key. An LSI can only be created when the base table is created and must be queried together with the base table partition key. Using a GSI with Product ID as the partition key and Review ID as the sort key will not allow the query to use a range of sort key values to find the highest ratings. Using an LSI with Product ID as the partition key and Product Rating as the sort key will not work because Product ID is not the partition key of the base table. Using an LSI with Review ID as the partition key and Product ID as the sort key will not allow the query to use a single partition key value to find the matching items.
Reference: [Global Secondary Indexes], [Querying]
A developer has code that is stored in an Amazon S3 bucket. The code must be deployed as an AWS Lambda function across multiple accounts in the same AWS Region as the S3 bucket an AWS CloudPormation template that runs for each account will deploy the Lambda function.
What is the MOST secure way to allow CloudFormaton to access the Lambda Code in the S3 bucket?
Solution:
This solution allows the CloudFormation service role to access the S3 bucket from any account, as long as it has the S3 GetObject permission. The bucket policy grants access to any principal with the GetObject permission, which is the least privilege needed to deploy the Lambda code. This is more secure than granting ListBucket permission, which is not required for deploying Lambda code, or using a service-based link, which is not supported for Lambda functions.
Reference: AWS CloudFormation Service Role, Using AWS Lambda with Amazon S3
Does this meet the goal?
Correct Answer:
A
A company has an application that runs as a series of AWS Lambda functions. Each Lambda function receives data from an Amazon Simple Notification Service (Amazon SNS) topic and writes the data to an Amazon Aurora DB instance.
To comply with an information security policy, the company must ensure that the Lambda functions all use a single securely encrypted database connection string to access Aurora.
Which solution will meet these requirements'?
Correct Answer:
A
This solution will meet the requirements by using IAM database authentication for Aurora, which enables using IAM roles or users to authenticate withAurora databases instead of using passwords or other secrets. The developer can use IAM database authentication for Aurora to enable secure database connections for all the Lambda functions that access Aurora DB instance. The developer can create an IAM role with permission to connect to Aurora DB instance and attach it to each Lambda function. The developer can also configure Aurora DB instance to use IAM database authentication and enable encryption in transit using SSL certificates. This way, the Lambda functions can use a single securely encrypted database connection string to access Aurora without needing any secrets or passwords. Option B is not optimal because it will store the credentials and read them from an encrypted Amazon RDS DB instance, which may introduce additional costs and complexity for managing and accessing another RDS DB instance. Option C is not optimal because it will store the credentials in AWS Systems Manager Parameter Store as a secure string parameter, which may require additional steps or permissions to retrieve and decrypt the credentials from Parameter Store. Option D is not optimal because it will use Lambda environment variables with a shared AWS Key Management Service (AWS KMS) key for encryption, which may not be secure or scalable as environment variables are stored as plain text unless encrypted with AWS KMS. References: [IAM Database Authentication for MySQL and PostgreSQL], [Using SSL/TLS to Encrypt a Connection to a DB Instance]
An organization is using Amazon CloudFront to ensure that its users experience low- latency access to its web application. The organization has identified a need to encrypt all traffic between users and CloudFront, and all traffic between CloudFront and the web application.
How can these requirements be met? (Select TWO)
Correct Answer:
BD
This solution will meet the requirements by ensuring that all traffic between users and CloudFront, and all traffic between CloudFront and the web application, are encrypted using HTTPS protocol. The Origin Protocol Policy determines how CloudFront communicates with the origin server (the web application), and setting it to “HTTPS Only” will force CloudFront to use HTTPS for every request to the origin server. The Viewer Protocol Policy determines how CloudFront responds to HTTP or HTTPS requests from users, and setting it to “HTTPS Only” or “Redirect HTTP to HTTPS” will force CloudFront to use HTTPS for every response to users. Option A is not optimal because it will use AWS KMS to encrypt traffic between CloudFront and the web application, which is not necessary or supported by CloudFront. Option C is not optimal because it will set the origin’s HTTP port to 443, which is incorrect as port 443 is used for HTTPS protocol, not HTTP protocol. Option E is not optimal because it will enable the CloudFront option Restrict Viewer Access, which is used for controlling access to private content using signed URLs or signed cookies, not for encrypting traffic.
References: [Using HTTPS with CloudFront], [Restricting Access to Amazon S3 Content by Using an Origin Access Identity]
A developer uses AWS CloudFormation to deploy an Amazon API Gateway API and an AWS Step Functions state machine The state machine must reference the API Gateway API after the CloudFormation template is deployed The developer needs a solution that uses the state machine to reference the API Gateway endpoint.
Which solution will meet these requirements MOST cost-effectively?
Correct Answer:
A
The most cost-effective solution is to use the DefinitionSubstitutions property of the AWS::StepFunctions::StateMachine resource to inject the API endpoint as a variable in the state machine definition. This way, the developer can use the intrinsic functionFn::GetAtt to get the API endpoint from the AWS::ApiGateway::RestApi resource, and pass it to the state machine without creating any additional resources or environment variables. The other solutions involve creating and managing extra resources, such as Secrets Manager secrets or AppConfig configuration profiles, which incur additional costs and complexity. References
✑ AWS::StepFunctions::StateMachine - AWS CloudFormation
✑ Call API Gateway with Step Functions - AWS Step Functions
✑ amazon-web-services aws-api-gateway terraform aws-step-functions
