AWS Fundamentals (IAM/EC2) Flashcards
AWS Regions
Clusters of data centres
AWS Availability Zones
Each region has many availability zones
They are geographically separated from each other
Connected with high bandwidth, low latency networking
IAM
Identity and Access Management
AWS Security - Users, Groups, Roles
IAM Role
One IAM Role per Application
IAM User
One IAM User per physical person
EC2
Virtual Machine in the cloud
Security Groups
Controls traffic in and out of EC2 Machines (protocols/ports)
Security Groups act as a firewall for EC2 instances
Locked down to a region
Inbound traffic is blocked by default while outbound traffic is authorised by default
Elastic IPs
Used for EC2 instances that need a fixed public IP
Elastic IP is lost once the instance is deleted
EC2 User Data
Runs a script when an EC2 instance is created
EC2 Launch Types
On Demand, Reserved (min 1 year), Spot Instances, Dedicated Instances. Dedicated Hosts
EC2 On Demand
Pay for what you use
Highest Cost but no upfront payment and no long term commitment
EC2 Reserved Instances
Up to 75% cheaper than On Demand
Reservation can be 1-3 years
EC2 Spot Instances
Up to 90% cheaper than On Demand
Most cost efficient instances in AWS
EC2 Dedicated Hosts
Physical EC2 Server
For companies with strong regulatory/compliance requirements
Spot Instance Requests
Define a max spot price and as long as the current spot price is below it you will get an instance
Or using Spot Block you can specify a block of time without any interruptions
Used for batch jobs, data analysis or workloads resistant to failure
Spot Fleet
Allows us to automatically request spot instances with the lowest price
EC2 Instance Types
R - more RAM (in memory cache)
C - more CPU (compute/databases)
M - balanced (medium) (general/web apps)
I - good I/O (instance storage/databases)
G - more GPU (video rendering/machine learning)
Burstable Instances
If a spike in CPU occurs, increase CPU with “burst credits”, if burst credits run out, then terminate the instance
AMI
Amazon Machine Images - ready to go virtual machines
Can be public and available on the Amazon Marketplace
AMI’s cost money to store, normally inexpensive
EC2 Placement Groups
Strategy to place your instances
- Clusters: Low latency group in the same AZ
- Spread: spread instances across underlying hardware (across AZ)
- Partition: spreads instances across different server tacks
ENI
Elastic Network Interface - virtual network card
Bound to one AZ
EC2 Hibernate
Preserve RAM, instance boots much faster
RAM size must be less than 150GB
