Amazon DVA-C02 Practice Test - Questions Answers, Page 15

The immutable deployment method is the best option for this scenario, because it meets the requirements of maintaining full capacity, avoiding service interruption, and minimizing the cost of additional resources.

The immutable deployment method creates a new set of instances in a separate Auto Scaling group and deploys the new version of the application to them. Then, it swaps the new instances with the old ones and terminates the old instances. This way, the application maintains full capacity during the deployment and avoids any downtime. The cost of additional resources is also minimized, because the new instances are only created for a short time and then replaced by the old ones.

The other deployment methods do not meet all the requirements:

The all at once method deploys the new version to all instances simultaneously, which causes a short period of downtime and reduced capacity.

The rolling with additional batch method deploys the new version in batches, but for the first batch it creates new instances instead of using the existing ones. This increases the cost of additional resources and reduces the capacity of the original environment.

The blue/green method creates a new environment with a new set of instances and deploys the new version to them. Then, it swaps the URLs between the old and new environments. This method maintains full capacity and avoids service interruption, but it also increases the cost of additional resources significantly, because it duplicates the entire environment.

The AWS Serverless Application Model (AWS SAM) comes built-in with CodeDeploy to provide gradual AWS Lambda deployments1. TheDeploymentPreferenceproperty in AWS SAM allows you to specify the type of deployment that you want. TheCanary10Percent10Minutesoption means that 10 percent of your customer traffic is immediately shifted to your new version.After 10 minutes, all traffic is shifted to the new version1.TheAutoPublishAliasproperty in AWS SAM allows AWS SAM to automatically create an alias that points to the updated version of the Lambda function1. Therefore, option A is correct.

Amazon API Gateway provides tools for creating and documenting web APIs that route HTTP requests to Lambda functions2. You can secure access to your API with authentication and authorization controls.Your APIs can serve traffic over the internet or can be accessible only within your VPC2.You can override the cache method in the selected stage of API Gateway2. Therefore, option B is correct.

Amazon Elastic Block Store (Amazon EBS) provides block level storage volumes for use with Amazon EC2 instances1.Amazon EBS encryption offers a straight-forward encryption solution for your EBS resources associated with your EC2 instances1.When you create an encrypted EBS volume and attach it to a supported instance type, the following types of data are encrypted: Data at rest inside the volume, all data moving between the volume and the instance, all snapshots created from the volume, and all volumes created from those snapshots1. Therefore, option A is correct.

The AWS Serverless Application Model Command Line Interface (AWS SAM CLI) is a command-line tool for local development and testing of Serverless applications2.Thesam local start-apisubcommand of AWS SAM CLI is used to simulate a REST API by starting a new local endpoint3. Therefore, option D is correct.

Amazon Simple Queue Service (Amazon SQS) is a fully managed queue service that allows you to de-couple and scale for applications1.Amazon SQS offers two types of queues: Standard and FIFO (First In First Out) queues1.The FIFO queue uses themessageDeduplicationIdproperty to treat messages with the same value as duplicate2. Therefore, changing the Amazon SQS standard queue to an Amazon SQS FIFO queue using the Amazon SQS message deduplication ID can help resolve the issue of the Lambda function processing some messages multiple times. Therefore, option A is correct.

The AWS Serverless Application Model Command Line Interface (AWS SAM CLI) is a command-line tool for local development and testing of Serverless applications3.Thesam local generate-eventcommand of AWS SAM CLI generates sample events for automated tests3.Thesam local invokecommand is used to invoke Lambda functions3. Therefore, option C is correct.

Amazon API Gateway allows you to create, deploy, and manage a RESTful API to expose backend HTTP endpoints, AWS Lambda functions, or other AWS services1.You can use API Gateway to perform basic validation of an API request before proceeding with the integration request1.When the validation fails, API Gateway immediately fails the request, returns a 400 error response to the caller, and publishes the validation results in CloudWatch Logs1.

To test changes before deploying to a production environment, you can modify the existing API to add request validation and deploy the updated API to a new API Gateway stage1. This allows you to perform tests without affecting the production environment.Once testing is complete and successful, you can then deploy the updated API to the API Gateway production stage1.

This approach has the least operational overhead as it avoids unnecessary creation of new APIs or exporting and importing of APIs.It leverages the existing infrastructure and only requires changes in the configuration of the existing API1.

Problem: Directory access without file names fails.

S3 Static Website Hosting:

Configuring S3 as a static website enables automatic serving ofindex.htmlfor directory requests.

Bucket policies ensure correct access permissions.

Updating the CloudFront origin simplifies routing.

Avoiding Public Exposure: The S3 website endpoint allows CloudFront to access content without making the bucket public.

S3 Static Website Hosting:https://docs.aws.amazon.com/AmazonS3/latest/userguide/WebsiteHosting.html