Amazon Web Services Updated CLF-C02 Exam Questions and Answers by josh

Amazon EC2 On-Demand Instances are ideal for unpredictable workloads that do not require a long-term commitment. This option allows users to pay for compute capacity by the hour or second, with no long-term commitments. It is suitable for short-term, spiky, or unpredictable workloads that cannot be interrupted and require flexibility. Option A is better suited for Reserved Instances, Option B is ideal for Spot Instances, and Option D is more suited for Reserved Instances due to cost optimization for long-term use.

"There is no long-term commitment required when you purchase On-Demand Instances. You pay only for the seconds that your On-Demand Instances are in the running state, with a 60-second minimum. The price per second for a running On-Demand Instance is fixed, and is listed on the Amazon EC2 Pricing, On-Demand Pricing page. We recommend that you use On-Demand Instances for applications with short-term, irregular workloads that cannot be interrupted." https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-on-demand-instances.html

Amazon EC2 instance store provides temporary block-level storage for your EC2 instance. This storage is located on disks that are physically attached to the host computer. Instance store is ideal for temporary storage of information that changes frequently, such as buffers, caches, scratch data, and other temporary content. It can also be used to store temporary data that you replicate across a fleet of instances, such as a load-balanced pool of web servers. An instance store consists of one or more instance store volumes exposed as block devices. The size of an instance store as well as the number of devices available varies by instance type and instance size. The virtual devices for instance store volumes are ephemeral[0-23]. Instance types that support one instance store volume have ephemeral0. Instance types that support two or more instance store volumes have ephemeral0, ephemeral1, and so on. Instance store pricing Instance store volumes are included as part of the instance’s usage cost. The data on an instance store volume persists even if the instance is rebooted. However, the data does not persist if the instance is stopped, hibernated, or terminated. When the instance is stopped, hibernated, or terminated, every block of the instance store volume is cryptographically erased. Therefore, do not rely on instance store volumes for valuable, long-term data. If you need to retain the data stored on an instance store volume beyond the lifetime of the instance, you need to manually copy that data to more persistent storage, such as an Amazon EBS volume, an Amazon S3 bucket, or an Amazon EFS file system. There are some events that can result in your data not persisting throughout the lifetime of the instance. The following table indicates whether data on instance store volumes is persisted during specific events, for both virtualized and bare metal instances1. References: Amazon EC2 instance store - Amazon Elastic Compute Cloud

AWS Storage Gateway is a hybrid cloud storage service that allows you to extend your on-premises file storage capabilities to the AWS Cloud. AWS Storage Gateway file gateway enables you to store and access your files in Amazon S3 using industry-standard file protocols such as NFS and SMB. File gateway caches frequently accessed files locally, providing low-latency access to your data. File gateway also optimizes the transfer of data between your on-premises environment and AWS, minimizing the amount of bandwidth consumed. By using file gateway, you can retain the performance benefit of sharing content locally while leveraging the scalability, durability, and cost-effectiveness of Amazon S3. References: AWS Storage Gateway, File Gateway

AWS Cloud Development Kit (AWS CDK) is a software development framework that allows you to define cloud resources as code using familiar programming languages, such as TypeScript, Python, Java, .NET, and Go (in Developer Preview). You can use AWS CDK to model your application resources using high-level constructs that provide sensible defaults and best practices, or use low-level constructs that provide full access to the underlying AWS CloudFormation resources. AWS CDK synthesizes your code into AWS CloudFormation templates that you can deploy using the AWS CDK CLI or the AWS Management Console. AWS CDK also integrates with other AWS services, such as AWS CodeCommit, AWS CodeBuild, AWS CodePipeline, AWS Lambda, Amazon EC2, Amazon S3, and more, to help you automate your development and deployment processes. AWS CDK is an open-source framework that you can extend and contribute to. References: Cloud Development Framework - AWS Cloud Development Kit - AWS, AWS Cloud Development Kit Documentation, AWS Cloud Development Kit - Wikipedia, AWS CDK Intro Workshop | AWS CDK Workshop