AWS EC2 High Level Overview β˜οΈπŸ’»

Compute 101:

Basic computer components:

  • OS (linux, osx)
  • CPU (processing power, brains)
  • Hard Drive (local storage)
  • Network card (internet access, ethernet or wifi)
  • Firewall (security, help block unauthorized things from accessing your computer)
  • RAM (short term memory, data loaded into this memory before processed)

Elastic Compute Cloud (EC2)

  • πŸ’» EC2 = basic computer, scalable (vertically and horizontally), config security and networking, and manage storage, elastic.

In EC2 terminology:

  • OS = AMI
  • CPU = Instance type
  • Hard drive = EBS (local storage)
  • Network card = IP Address (internet access)
  • Firewall = Security groups
  • RAM = RAM

How are we charged?

  • Purchase instances on demand, or reserved basis (cheaper but locked into a longer term contract for the instance duration)
  • Spot instances = only pay for instance when price is at or below a price threshold β€” gives you discount for unused instances (charged by the minute)
  • Instance Types: general purpose, compute optimized, accelerated computing, memory optimized, and storage optimized.
  • EBS optimized = option for higher IOPS performance
  • AMI type = which OS you want with diff prices for diff OS’s / versions
  • Data transfer = charged for how much data moving in/out of the instance
  • Region = where the instance is provisioned (priced differently per region)

AMIs and EBS

  • Amazon Machine Image (AMI) = OS = pre configured package required to launch EC2 instance.
  • AMI is like a template with the desired server environment (and can spin up as many instances as you want/need from any template AMI)
  • Community AMIs = free to use, usually just the OS
  • AWS marketplace AMIs = pay to use, comes packaged with additional software you want to use usually
  • My AMIs = custom created AMIs
  • AMI components: 1. Root Volume template (OS and software), 2. Launch Permissions, 3. Block device mapping (EBS or hard drive mapping for storage)
  • Can add storage to EC2 instances using Elastic Block Store (EBS)
  • EBS = storage volume for instances, like a hard drive. Highly available, must be in the same AZ as the instance. Can persist past the life of the instance.

Security Groups (SGs)

  • SGs = allow or deny traffic
  • SGs are on the instance level.
  • Different from NACLs
  • SGs are like virtual firewalls that controls the traffic for instances. When you launch an instance you associate one or more SGs with the instance.
  • SGs start with all deny traffic rules, and add rules to allow traffic.
  • Remember, NACLs are at the subnet level.

Connecting to your EC2 Instances:

1. Create key pair (.pem) when launching instance and save to your local machine.

2. Run β€˜chmod 400 sshkeypair.pem’ to change permissions on a mac

3. Connect to instance using DNS name or public IP address: run command β€˜ssh -i β€œsshkeypair.pem” ec2-user@ec2–54–196–0–138.compute-1.amazonaws.com’

Now you are connected to instance on the CLI

Once connected you will see the private IP on the command line.

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