Jiaxi Liu (Jesse)

Master’s Graduate

Software Engineer | Scalable APIs · Web Scraping · Data Integration · Code Quality & Refactoring

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AWS CLF-C02 Review: EC2, Instance Types, AMI, Pricing, Auto Scaling, and Messaging

EC2 is AWS's virtual server service. Instances can be created, started, stopped, and terminated on demand.

How EC2 Works

When creating an EC2 instance, you usually choose:

  • AMI: operating system and preinstalled software
  • Instance type: CPU, memory, and networking capacity
  • Storage configuration
  • Network and security groups

You can connect through SSH, RDP, or AWS Systems Manager.

Instance Types

General purpose: balanced compute, memory, and networking. Good for web services.

Compute optimized: high CPU workloads.

Memory optimized: large datasets, caches, and databases.

Accelerated computing: GPU or hardware acceleration.

Storage optimized: high I/O and local storage workloads.

Pricing Models

Common pricing options:

  • On-Demand Instances
  • Reserved Instances
  • Savings Plans
  • Spot Instances

Choose based on whether the workload is stable, interruptible, and long-running.

Auto Scaling and Load Balancing

Auto Scaling automatically adds or removes instances based on demand.

Elastic Load Balancing distributes traffic across multiple targets to improve availability.

Messaging Services

SQS is a queue service for decoupling producers and consumers.

SNS is a pub/sub service for pushing messages to multiple subscribers.

EventBridge supports event-driven architectures across AWS services and applications.