DVA-C01 (Page 20)

A company is developing a publicly accessible single-page application.The application makes calls from a client web browser to backend services to provide a user interface to customers.The application depends on a third-party web service exposed as an HTTP API.The web client must provide an API key to the third-party web service by using the HTTP header as part of the HTTP request.The company’s API key must not be exposed to the users of the web application.Which solution will meet these requirements MOST cost-effectively?Read More →

A company has a three-tier application that is deployed in Amazon Elastic Container Service (Amazon ECS).The application is using an Amazon RDS for MySQL DB instance.The application performs more database reads than writes.During times of peak usage, the application’s performance degrades.When this performance degradation occurs, the DB instance’s ReadLatency metric in Amazon CloudWatch increases suddenly.How should a developer modify the application to improve performance?Read More →

A calendar application gives users the ability to schedule and share events.The application stores its data in several Amazon DynamoDB tables.The Events table stores all events for the application.The Events table has a primary key in which the partition key is the date of the event and the sort key is the user’s unique ID number.A developer is working on a dashboard that will show each user all the details for all their events scheduled on a single day.The developer needs to get the data from the Events table.What should the developer do to get the relevant data MOST efficiently?Read More →

A developer is building a three-tier application with an Application Load Balancer (ALB), Amazon EC2 instances, and Amazon RDS.There is an alias record in Amazon Route 53 that points to the ALB.When the developer tries to access the ALB from a laptop, the request times out.Which logs should the developer investigate to verify that the request is reaching the AWS network?Read More →

An ecommerce company is using an AWS Lambda function behind Amazon API Gateway as its application tier.To process orders during checkout, the application calls a POST API from the frontend.The POST API invokes the Lambda function asynchronously.In rare situations, the application has not processed orders.The Lambda application logs show no errors or failures.What should a developer do to solve this problem?Read More →

A developer at a company recently created a serverless application to process and show data from business reports.The application’s user interface (UI) allows users to select and start processing the flies.The UI displays a message when the result is available to view.The application uses AWS Step Functions with AWSLambda functions to process the files.The developer used Amazon API Gateway and Lambda functions to create an API to support the UI.The company’s UI team reports that the request to process a file s often returning timeout errors because of the size or complexity of the files.The UI team wants the API to provide an immediate response so that the UI can display a message while the files are being processed.The backend process that is invoked by theAPI needs to send an email message when the report processing is complete.What should the developer do to configure the API to meet these requirements?Read More →

A developer has an application that asynchronously invokes an AWS Lambda function.The developer wants to store messages that resulted in failed invocations of the Lambda function so that the application can retry the call later.What should the developer do to accomplish this goal with the LEAST operational overhead?Read More →

A developer is designing an Amazon DynamoDB table for an application.The application will store user information that includes a unique identifier and an email address for each user.The application must be able to query the table by using either the unique identifier or the email address.How should the developer design the DynamoDB table to meet these requirements?Read More →

A developer is working on a web application that runs on Amazon Elastic Container Service (Amazon ECS) and uses an Amazon DynamoDB table to store data.The application performs a large number of read requests against a small set of the table data.How can the developer improve the performance of these requests? (Choose two.)Read More →

A development team has been using a builder server that is hosted on an Amazon EC2 instance to perform builds and deployments for the last 3 months.TheEC2 instance’s instance profile uses an IAM role that contains the Administrator Access managed policy.The development team must replace that policy with a policy that provides only the required permissions.What is the FASTEST way to create a custom 1AM policy for the EC2 instance to meet this requirement?Read More →