12 - Lambda

A startup company has a serverless architecture that uses AWS Lambda, API Gateway, and DynamoDB. They received an urgent feature request from their client last month and now, it is ready to be pushed to production. The company is using AWS CodeDeploy as their deployment service. Which of the following configuration types will allow you to specify the percentage of traffic shifted to your updated Lambda function version before the remaining traffic is shifted in the second increment?

Canary

Your customer is building an internal application that serves as a repository for images uploaded by a couple of users. Whenever a user uploads an image, it would be sent to Kinesis for processing before it is stored in an S3 bucket. Afterwards, if the upload was successful, the application will return a prompt telling the user that the upload is successful. The entire processing typically takes about 5 minutes to finish. Which of the following options will allow you to asynchronously process the request to the application in the most cost-effective manner?

Create a Lambda function that will asynchronously process the requests.

Your company has recently deployed a new web application which uses a serverless-based architecture in AWS. Your manager instructed you to implement CloudWatch metrics to monitor your systems more effectively. You know that Lambda automatically monitors functions on your behalf and reports metrics through Amazon CloudWatch. In this scenario, what types of data do these metrics monitor?

Invocations & Errors

A popular social media website uses a CloudFront web distribution to serve their static contents to their millions of users around the globe. They are receiving a number of complaints recently that their users take a lot of time to log into their website. There are also occasions when their users are getting HTTP 504 errors. You are instructed by your manager to significantly reduce the user's login time to further optimize the system. Which of the following options should you use together to set up a cost-effective solution that can improve your application's performance? (Choose 2)

- Customize the content that the CloudFront web distribution delivers to your users using Lambda@Edge, which allows your Lambda functions to execute the authentication process in AWS locations closer to the users. - Set up an origin failover by creating an origin group with two origins. Specify one as the primary origin and the other as the second origin which CloudFront automatically switches to when the primary origin returns specific HTTP status code failure responses.

You have a VPC that has a CIDR block of 10.31.0.0/27 which is connected to your on-premises data center. There was a requirement to create a Lambda function that will process massive amounts of cryptocurrency transactions every minute and then store the results to EFS. After you set up the serverless architecture and connected Lambda function to your VPC, you noticed that there is an increase in invocation errors with EC2 error types such as EC2ThrottledException on certain times of the day. Which of the following are the possible causes of this issue?

- You only specified one subnet in your Lambda function configuration. That single subnet runs out of available IP addresses and there is no other subnet or Availability Zone which can handle the peak load. - Your VPC does not have sufficient subnet ENIs or subnet IPs.

You are leading a software development team which uses serverless computing with AWS Lambda to build and run applications without having to set up or manage servers. You have a Lambda function that connects to a MongoDB Atlas, which is a popular Database as a Service (DBaaS) platform and also uses a third party API to fetch certain data for your application. You instructed one of your junior developers to create the environment variables for the MongoDB database hostname, username, and password as well as the API credentials that will be used by the Lambda function for DEV, SIT, UAT and PROD environments. Considering that the Lambda function is storing sensitive database and API credentials, how can you secure these information to prevent other developers in your team, or anyone, from seeing these credentials in plain text? Select the best option that provides the maximum security.

Create a new KMS key and use it to enable encryption helpers that leverage on AWS Key Management Service to store and encrypt the sensitive information.

You are working as a Solutions Architect for a leading data analytics company in which you are tasked to process real-time streaming data of your users across the globe. This will enable you to track and analyze globally-distributed user activity on your website and mobile applications, including click stream analysis. Your cloud architecture should process the data in close geographical proximity to your users and to respond to user requests at low latencies. Which of the following options is the most ideal solution that you should implement?

Integrate CloudFront with Lambda@Edge in order to process the data in close geographical proximity to users and respond to user requests at low latencies. Process real-time streaming data using Kinesis and durably store the results to an Amazon S3 bucket.

An application is using a Lambda function to process complex financial data which runs for about 10 to 15 minutes. You noticed that there are a few terminated invocations throughout the day, which caused data discrepancy in the application. Which of the following is the most likely cause of this issue?

The failed Lambda functions have been running for over 15 minutes and reached the maximum execution time.

A game development company operates several virtual reality (VR) and augmented reality (AR) games which use various RESTful web APIs hosted on their on-premises data center. Due to the unprecedented growth of their company, they decided to migrate their system to AWS Cloud to scale out their resources as well to minimize costs. Which of the following should you recommend as the most cost-effective and scalable solution to meet the above requirement?

Use AWS Lambda and Amazon API Gateway.