Newly Released Amazon Web Services DVA-C02 Exam PDF

The best solution for publishing an API without an integrated backend is to use the MOCK integration type in API Gateway. This allows the developer to return a static response to the client without sending the request to a backend service. The developer can configure the method integration request and integration response to associate a response with an HTTP status code, such as 200 OK or 404 Not Found. The developer can also create an API Gateway stage and deploy the API to make it available to the teams that depend on the application backend. The other solutions are either not feasible or not efficient. Creating an AWS Lambda function, an EC2 application, or an AWS Lambda layer would require additional resources and code to generate the mocked responses and HTTP status codes. These solutions would also incur additional costs and complexity, and would not leverage the built-in functionality of API Gateway. References

• Set up mock integrations for API Gateway REST APIs
• Mock Integration for API Gateway - AWS CloudFormation
• Mocking API Responses with API Gateway
• How to mock API Gateway responses with AWS SAM

Amazon API Gateway is a service that enables developers to create, publish, maintain, monitor, and secure APIs at any scale. Amazon CloudWatch is a service that monitors AWS resources and applications. API Gateway provides several CloudWatch metrics to help developers troubleshoot issues with their APIs. Two of the metrics that can help the developer troubleshoot the issue of API Gateway timing out are:

• IntegrationLatency: This metric measures the time between when API Gateway relays a request to the backend and when it receives a response from the backend. A high value for this metric indicates that the backend is taking too long to respond and may cause API Gateway to time out.
• Latency: This metric measures the time between when API Gateway receives a request from a client and when it returns a response to the client. A high value for this metric indicates that either the integration latency is high or API Gateway is taking too long to process the request or response.

References:

• [What Is Amazon API Gateway? - Amazon API Gateway]
• [Amazon API Gateway Metrics and Dimensions - Amazon CloudWatch]
• [Troubleshooting API Errors - Amazon API Gateway]

• A feature branch is a branch that is created from the main branch to work on a specific feature or task1. Feature branches allow developers to isolate their work from the main branch and avoid conflicts with other changes1. Feature branches can be merged back to the main branch when the feature or task is completed and tested1.
• In this scenario, the developer needs to maintain two parallel streams of work: one for fixing and updating the current version of the application that is deployed in production, and another for developing the new version of the application. The developer can use feature branches to achieve this goal.
• The developer can create a feature branch from the main branch for production bug fixes. This branch will contain the code that is currently deployed in production, and any fixes or updates that need to be applied to it. The developer can push this branch to the CodeCommit repository and use it to deploy changes to the production environment.
• The developer can also create a second feature branch from the main branch for development of the new version of the application. This branch will contain the code that is under development for the new version, and any changes or enhancements that are part of it. The developer can push this branch to the CodeCommit repository and use it to test and deploy the new version of the application in a separate environment.
• By using feature branches, the developer can keep the main branch stable and clean, and avoid mixing code from different versions of the application. The developer can also easily switch between branches and merge them when needed.

The correct answer is C. The developer did not update the Docker image tag to a new version.

C. The developer did not update the Docker image tag to a new version. This is correct. When deploying an application to Amazon EKS, the developer needs to specify the Docker image tag that contains the application code and configuration. If the developer does not update the Docker image tag to a new version after making changes to the application, the EKS cluster will continue to use the old Docker image tag that references the original backend resources. To fix this issue, the developer should update the Docker image tag to a new version and redeploy the application to the EKS cluster.

A. The developer did not successfully create the new AWS account. This is incorrect. The creation of a new AWS account is not related to the application’s connection to the backend resources. The developer can use any AWS account to host the EKS cluster and the backend resources, as long as they have the proper permissions and configurations.

B. The developer added a new tag to the Docker image. This is incorrect. Adding a new tag to the Docker image is not enough to deploy the changes to the application. The developer also needs to update the Docker image tag in the EKS cluster configuration, so that the EKS cluster can pull and run the new Docker image.

D. The developer pushed the changes to a new Docker image tag. This is incorrect. Pushing the changes to a new Docker image tag is not enough to deploy the changes to the application. The developer also needs to update the Docker image tag in the EKS cluster configuration, so that the EKS cluster can pull and run the new Docker image.

References:

• 1: Amazon EKS User Guide, “Deploying applications to your Amazon EKS cluster”, https://docs.aws.amazon.com/eks/latest/userguide/deploying-applications.html
• 2: Amazon ECR User Guide, “Pushing an image”, https://docs.aws.amazon.com/AmazonECR/latest/userguide/docker-push-ecr-image.html
• 3: Amazon EKS User Guide, “Updating an Amazon EKS cluster”, https://docs.aws.amazon.com/eks/latest/userguide/update-cluster.html