Intro

• Regional Service
• Infrastructure as a Service (IaaS)
• Stopping & Starting an instance may change its public IP but not its private IP
• AWS Compute Optimizer recommends optimal AWS Compute resources for your workloads
• There is a vCPU-based On-Demand Instance soft limit per region

User Data

• Bootstrap script (runs on the first launch)
• Used to automate dynamic boot tasks (that cannot be done using AMIs)
  • Installing updates
  • Installing software
  • Downloading common files from the internet
• Runs with the root user privilege

Instance Classes

• General Purpose
  • Great for a diversity of workloads such as web servers or code repositories
  • Balance between compute, memory & networking
• Compute Optimized
  • Great for compute intensive tasks
    • Batch Processing
    • Media Transcoding
    • HPC
    • Gaming Servers
• Memory Optimized
  • Great for in-memory databases or distributed web caches
• Storage Optimized
  • Great for storage intensive tasks (accessing local databases)
    • OLTP systems
    • Distributed File System (DFS)

Security Groups

• Only contain Allow rules
• External firewall for EC2 instances (applied on ENI, if a request is blocked by SG, instance will never know)