AWS Essentials Flashcards
What is AMI?
An Amazon Machine Image (AMI) is a special type of virtual appliance provided by Amazon Web Services (AWS) that is used to create a virtual machine (VM) within the Elastic Compute Cloud (EC2) service. An AMI includes the following components:
- Root Volume Template: This is typically an operating system image, which can also include applications or software configurations.
- Launch Permissions: Controls which AWS accounts can use the AMI to launch instances.
- Block Device Mapping: Specifies the volumes to attach to the instance when it is launched, such as the root volume and additional data volumes.
https://www.notion.so/Section-4-Module-Two-AWS-Foundation-Services-14b91027971c801c9bf8cdd6478f09d0
What are the Key Features of AWS AMI?
- Pre-configured Templates: AMIs can be pre-configured with software, operating systems, and configurations to streamline deployments.
- Custom AMIs: Users can create custom AMIs from existing EC2 instances, capturing the state and configuration for reproducible environments.
- Region-Specific: AMIs are specific to an AWS region. However, they can be copied to other regions if needed.
- Public or Private: AMIs can be public (available to all AWS users) or private (available only to your AWS account or specific AWS accounts).
https://www.notion.so/Section-4-Module-Two-AWS-Foundation-Services-14b91027971c801c9bf8cdd6478f09d0
What are theTypes of AMIs?
- Amazon Linux AMI: A Linux image provided and maintained by AWS.
- Marketplace AMIs: These are available through the AWS Marketplace and often include licensed software.
- Community AMIs: Publicly shared by other AWS users.
- Custom AMIs: Created by users for specific use cases.
https://www.notion.so/Section-4-Module-Two-AWS-Foundation-Services-14b91027971c801c9bf8cdd6478f09d0
What are the Use Cases of AMI?
- Rapid Deployment: Easily spin up multiple instances with the same configuration.
- Backup and Recovery: Capture the state of an instance for backup purposes.
- Scaling: Quickly scale applications by launching multiple instances from the same AMI.
- DevOps and Automation: Automate infrastructure setup using pre-configured AMIs.
Using AMIs effectively enables streamlined, scalable, and automated cloud infrastructure deployment on AWS.
https://www.notion.so/Section-4-Module-Two-AWS-Foundation-Services-14b91027971c801c9bf8cdd6478f09d0
What is AWS EBS?
Amazon Elastic Block Store (EBS) is a block storage service provided by Amazon Web Services (AWS) designed for use with Amazon EC2 instances. It offers persistent, high-performance, and scalable block storage that can be used for a wide variety of workloads.
https://www.notion.so/Section-4-Module-Two-AWS-Foundation-Services-14b91027971c801c9bf8cdd6478f09d0
What is the main difference between EC2 Instance Store and Amazon EBS?
EC2 Instance Store: Temporary (ephemeral) storage. Data is lost if the instance is stopped, hibernated, or terminated.
EBS: Persistent storage. Data remains intact across instance stops, reboots, or terminations (if the volume is not deleted).
When to Use EC2 Instance Store?
Temporary Storage Needs: For data that doesn’t need to persist after instance termination.
High Performance: For applications that require very high I/O performance and can handle data loss, such as caches, buffers, or temporary logs.
Cost Efficiency: When you need high-speed storage included with the instance at no extra cost.
When to Use Amazon EBS:
Persistent Storage: For data that must survive instance reboots, stops, or terminations.
Backup and Recovery: With EBS snapshots for disaster recovery or backups.
Scalable and Flexible Storage: When you need flexible storage options with varying performance characteristics.
Data Durability: For critical applications like databases or enterprise applications that require consistent and reliable data storage.
What is Step Functions?
AWS Step Functions is a serverless orchestration service provided by Amazon Web Services (AWS). It lets you coordinate multiple AWS services and define workflows as state machines. With Step Functions, you can break down complex processes into individual steps and manage their execution, making it easier to build, monitor, and debug your applications.
What are the key features of Step Functions?
1- State Machine Definition: You define workflows using the Amazon States Language (JSON-based), describing each step and its transitions.
2-Integration with AWS Services: Step Functions integrates with many AWS services (e.g., Lambda, DynamoDB, ECS, S3) to orchestrate their operations.
3-Execution Types:
Standard Workflows: Suitable for long-running or complex processes.
Express Workflows: Designed for high-volume, short-duration workflows.
4-Error Handling and Retries: Built-in mechanisms to handle errors, retry logic, and timeouts for failed steps.
5-Parallelism: Support for running multiple branches of a workflow in parallel.
6-Visualization: Provides a visual interface in the AWS Management Console to monitor the execution and status of workflows.
7-Serverless: Automatically scales with your workload and charges you only for what you use.
Cite examples of Step Functions use cases.
‘-ETL Pipelines: Automate data extraction, transformation, and loading processes.
2-Microservices Coordination: Manage workflows that span multiple microservices.
3-Batch Processing: Orchestrate batch jobs like video encoding or data analysis.
4-Automation: Implement business processes or automate DevOps workflows.
5-Machine Learning Pipelines: Coordinate data preprocessing, model training, and deployment.
What is the difference between state machine and workflow?
1) A state machine is a mathematical model of computation used to design systems that can be in one of a finite number of states at any given time. It transitions between states based on events or conditions.
2) A workflow represents a sequence of tasks or activities that must be completed to achieve a specific outcome. It is more process-oriented and is often visualized as a series of steps or actions.
What is ASL?
Amazon States Language, also known as ASL, is a language for programming step functions.
Step Functions: What are flow states?
Flow states control the flow of execution of the steps. For example, Choice states provide conditional logic; Wait states pause workflow execution; Map states run child workflows for each item in a dataset; and Parallel states create separate branches in your workflows.
Step Functions: What are Task states?
Task states represent a unit of work that another AWS service performs, such as calling another AWS service or API. Tasks states are also known as Actions. You can choose hundreds of actions to perform work in AWS and external services. (Note: You can also use workers that run outside of Step Functions to perform tasks. For more info, see Activities.)
What are the AWS services that can invoke step functions?
-AWS Lambda, using the StartExecution call.
-Amazon API Gateway
-Amazon EventBridge
-AWS CodePipeline
-AWS IoT Rules Engine
-AWS Step Functions
