1. What is Amazon S3?

• Managed cloud storage service by AWS, storing data as objects in buckets.
• Objects can be any file (documents, images, videos), each with a unique object key.
• Designed for 99.999999999% durability (11 9s).
  This extremely high durability means that if you store 10 million objects, you can expect to lose one object every 10,000 years on average.
• Virtually unlimited storage; each object can be up to 5 TB.

2. Key Features

• Private by default: Data privacy controlled through access permissions.
• Stores data redundantly across multiple facilities.
• Access data from anywhere via HTTP/HTTPS.
• Globally unique bucket names.
• Integration with AWS services, accessed through:
  • AWS Management Console
  • AWS CLI
  • AWS SDKs
  • REST API endpoints
• The Bucket names should be unique

3. Amazon S3 Storage Classes

• Amazon S3 Standard: General-purpose storage for frequently accessed data.
• Amazon S3 Intelligent-Tiering: Auto-moves data to lower-cost tiers when access drops.
• Amazon S3 Standard-IA (Infrequent Access): For less frequently accessed but readily available data.
• Amazon S3 One Zone-IA: Low-cost, single-AZ storage for infrequent data access.
• Amazon S3 Glacier: Affordable data archiving with variable retrieval times.
• Amazon S3 Glacier Deep Archive: Lowest-cost storage for long-term data retention with 12-hour retrieval.

4. Access & URLs

• Data Access Methods: AWS Console, CLI, SDKs, REST endpoints.
• URL Structure:
  • Format: https://[bucket name].s3.[region].amazonaws.com/[object key]
  • Example: Bucket in Tokyo region:
    • URL: https://my-bucket.s3.ap-northeast-1.amazonaws.com/my-object.jpg
• URLs are Region-specific, ensuring data locality.

5. Data Redundancy & Durability

• Data stored across multiple facilities in the selected Region.
• Built to withstand loss of two facilities without data loss.

6. Scaling & Performance

• Auto-scales to accommodate data growth.
• No provisioning of storage or throughput required.
• Charges based on usage.

7. Common Use Cases

• Application Assets Storage: Common storage for application files.
• Static Web Hosting: Host static websites with HTML, CSS, JS.
• Backup & Disaster Recovery: Reliable backup storage with high durability.
• Big Data Analytics: Scalable storage for big data workflows.

8. Amazon S3 Pricing

• Pricing based on:
  • Storage Usage: Cost per GB per month for each storage class.
  • Data Transfer: Charges for data transfer out of AWS Regions.
  • Operations: PUT, GET, LIST, and COPY operations.
• Free of Charge:
  • Data transferred into Amazon S3.
  • Transfers out to CloudFront or EC2 within the same Region.

9. Cost Factors

• Storage Class: Costs differ for Standard, IA, Glacier, etc.
• Amount of Data: Number and size of stored objects.
• Request Types: Charges for API operations like GET, PUT, COPY.
• Data Transfer: Free inbound; charges for outbound to different Regions.

EC2 (Elastic compute cloud)

• Cloud VMs: Virtual machines (EC2 instances) in the AWS Cloud for scalable computing.
• Guest OS Control: Full control over Windows or Linux operating systems.
• Elastic Scaling: Easily scale the number and size of instances to meet demand.
• Quick Deployment: Launch instances quickly from AMIs across global regions.
• Traffic Management: Use security groups to control inbound and outbound traffic.
• EC2 = IaaS: Provides complete control over OS and infrastructure (Infrastructure as a Service).

AWS Compute Categories

• VMs: EC2 and Lightsail provide virtual servers.
• Containers: Amazon ECS for Docker containers, Fargate for serverless containers.
• PaaS: Elastic Beanstalk simplifies app deployment without managing infrastructure.
• Serverless: AWS Lambda runs code without provisioning or managing servers.
• Specialized: AWS Outposts for on-premises infrastructure, AWS Batch for large-scale batch jobs.

Key EC2 Concepts

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• AMI (Amazon Machine Images): Pre-configured templates for launching instances with OS and software.
  • Types: Quick Start (AWS defaults), My AMIs (your custom images), AWS Marketplace (third-party apps), Community AMIs (user-shared, be cautious).
• Instance Types: Define CPU, memory, and storage, optimized for different workloads.
  • Categories: General Purpose, Compute Optimized, Memory Optimized, Storage Optimized, Accelerated Computing (GPU-based).
• Security Groups: Virtual firewall to control traffic to/from EC2 instances.
• Key Pairs: Public/Private key pairs for secure SSH access to EC2 instances.

Steps to Launch an EC2 Instance

1. Select an AMI: Choose a pre-built or custom AMI that matches your app requirements.
2. Choose an Instance Type: Select based on CPU, memory, and performance needs.
3. Configure Network Settings: Set VPC, subnet, and public IP (if needed).
4. Attach an IAM Role (Optional): Add permissions to allow instance access to other AWS services.
5. Add a User Data Script (Optional): Customize the instance setup, like installing software.
6. Specify Storage: Set up root and additional volumes (EBS storage).
7. Add Tags: Use tags to organize and identify instances for management.
8. Configure Security Groups: Set rules for inbound/outbound traffic.
9. Select or Create a Key Pair: Secure access to the instance using the key pair.

EC2 Instance Lifecycle States

• Pending: Instance is being launched.
• Running: Instance is live and operational.
• Rebooting: Instance is rebooting.
• Shutting Down: Instance is in the process of shutting down.
• Terminated: Instance has been permanently deleted.
• Stopping: Instance is being stopped (can be restarted).
• Stopped: Instance is stopped but can be started again.

EC2 Pricing Models

• On-Demand: Pay by the hour/second without long-term commitment.
• Reserved: Save money by reserving instances for 1-3 years at a discounted rate.
• Spot: Bid on unused capacity at lower rates, with possible interruptions.
• Dedicated Hosts: Rent entire physical servers, ideal for specific licensing requirements.
• Dedicated Instances: Isolated from other customers’ instances at the hardware level.

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Instance Naming Convention and types

• Example: t3.micro – ‘T’ for General Purpose, ‘3’ for generation, ‘micro’ for instance size.
  • T3 Micro: 2 vCPUs, 1 GB memory (light apps).
  • T3 Small: 2 vCPUs, 2 GB memory (moderate apps).

Note: T3 instances can burst CPU usage beyond the baseline when needed.

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