Elastic Compute Cloud (EC2)

EC2

AMIs = OS

Instance Type = Processing Power

EBS = Local Storage

IP Adressing

Security Groups = Firewall

RAM = RAM

Purchasing Options (Most Common)

On Demand

1. Most Expensive
2. Most Flexible
3. Charged when running and per hour
4. Provision/Terminate on Demand

Reserved

1. Purchase instance for 1 or 3 years
2. Significant price discount
3. Pay upfornt/partial/nothing up front
4. Once purchased you pay the full price regardless of how often you use it.

Spot Pricing

1. You bid for a price and only pay when instance price is equal to or below bid price
2. Allows to purchase unused instances for short time at substantial discount
3. Price fluctuates due to supply and demand
4. Charged by the minute
5. Instance provisioned when matching your bid
6. Instance terminates when spot price exceeds your bid.

How are you charged

Purchasing Options

• On Demand
• Reserved
• Spot

Instance Type

• General Purpose
• Compute Optimized
• GPU Optimized
• Memory Optimized
• Storage Optimized

EBS Optimized

• For high IOPS

AMI Type (Amazone Machine Images)

• Linux
• Windows

5. Data Transfer

• In/Out of instance

6. Region

• The area your instance is in.

AMIs (Amazone Machine Images)

AMIs are preconfigured instances with OS, software package and other required settings

AMI Components

Root Volume Template

• Operating System
• Application Software

Launch Permissions

Block Device Mappings

• EBS

Creating an AMI instance essentially creates an image you can use to create other instances

AMI Categories

• Community AMIs - Free to use and generally just the OS
• AWS Market Place - Paid for and comes with licensed software
• My AMIs - You create yourself

Instance Types

These are the hardware specs

Components

Family

• Categorised optimisation like "General Purpose", "Compute Optimised"

Type

• Subcategory for Family like t2.nano, m5.xlarge

vCPUs

• No. CPUs

Memory Gib

• Amount of memory

Instance Storage GB

• Local Storage

EBS-Optimised Available

• Shows if this an option for the instance. Provides better performance

Network Performance

• Based on network bandwidth

Elastic Block Storage (EBS)

Attached Storage

Every EC2 instance must have a root volume which might not be EBS

Default is to delete EBS root volumes when the instance is terminated. Can be changed

Additional EBS volumes can be added

Additional EBS volumes can be attached or detached at any time and is not deleted by default when the instance is terminated

Snapshots

A backup of an EBS volume from a moment in time

Not an active EBS volume and cannot be attached/detached

To restore snapshot, create a new EBS with the snapshot as a template

Security Groups

SGs Allow/Deny traffic from an instance level

All security groups evaluated before being allowed/denied

Default SG allows all in and out

New SG has deny all in and allow all out

All traffic denied unless there is a specific allow rule

There are no deny rules, only allow rules

IP Addressing

Instances can be launched with or without IP addresses

Public IP required to access the internet.

Default VPC and Subnets configured so all new instances have public IP addresses