Ref: https://learn.cantrill.io/courses/1820301/lectures/41301620

DEMO: https://learn.cantrill.io/courses/1820301/lectures/41301621 and https://learn.cantrill.io/courses/1820301/lectures/41301622

• Summary
• Contents:

Amazon EC2 - Key Concepts

• 🔧 AWS's default compute service
  • IaaS (Infrastructure-as-a-Service) → OS is the unit of consumption
  • Customers provision instances, which are deployed inside physical EC2 hosts
    • Instances can also be called virtual machines (VMs) or virtual servers (VSs)
    • Customers only manage instances, AWS manages hosts (exception: dedicated EC2 hosts, which are managed by customers)
• ❗ Instances are deployed in VPC subnets
  • EC2 is private by default
  • EC2 is AZ-resilient

EC2 Instances

• An instance is a virtual machine (VM)
  • Customer provisions OS
  • Runtime Environment (RTE), DB dependencies, apps… can also be configured inside an instance
• Size & capabilities configured at launch time
  • 💡 some capabilities can also be configured after launch
• Default billing: On-Demand Billing → “per-second instance fee”
  • customers charged for consumed resources per unit of time (usually seconds)
• NWing: deployed in VPC subnets
  • Private by default
  • Public access must be configured if desired
• Storage:
  • Local on-host block storage (Instance Store)
  • External off-host block storage via Amazon EBS (Elastic Block Store)

EC2 Instance State

• State = indication of the condition of the instance

• Three states:
  1. Running (Active)
     • Billed for storage, CPU, NWing & memory
  2. Stopped (Inactive)
     • Billed only for storage
     • Can be restarted
  3. Terminated (Deleted)
     • Full deletion → non-reversible action
       • can no longer be restarted
     • No more billing/charges