EC2 Flashcards
What is an On-Demand Instance?
An instance that allows you to pay by the hour/second with no commitment
What is a Reserved Instance?
An instance with reserved capacity that provides significant discounts to On-Demand. Requires 1-3 year contract.
What is a Spot Instance?
Allows you to bid a price for an instance, providing greater savings. Good if you have flexible start/end times.
What are Dedicated Hosts?
Physical EC2 servers dedicated to your use. Usually used by government etc.
What is the charge when a Spot Instance is terminated?
If AWS terminates, you will not be charged for a partial hour. If you terminate, you will be charged for the full hour.
What are the 3 types of Load Balancer available?
Application Load Balancer (ALB)
Network Load Balancer (NLB)
Classic Load Balancer (ELB)
Define the Application Load Balancer
Operates at layer 7, and best suited to HTTP/HTTPS traffic.
Define the Network Load Balancer
Operates at layer 4, and best suited to TCP traffic where extreme performance is required.
Define the Classic Load Balancer
Uses features such as X-Forwarded-For header and sticky sessions.
What is EFS?
A File Storage Service for EC2
What are the 2 types of Placement Groups?
Clustered Placement Groups
Spread Placement Groups
What is a Clustered Placement Group?
A group of instances in a single Availability Zone. Best suited to apps relying on low latency such as Big Data.
What is a Spread Placement Group?
A group of instances that are on their owndistinct hardware, kept separate.
What is the endpoint to get instance metadata?
http://169.254.169.254/latest/meta-data/
Can an EBS Volume be in a different AZ to an instance?
No
What is the difference between a snapshot and an image?
A snapshot is for backup
An image is for booting a new instance
What are the 2 steps to copy a volume from one Availability Zone to another?
Create a snapshot of the Volume
Create a new Volume using the snapshot, selecting the desired Availability Zone in the process.
What are the 3 steps to migrate an instance from one region to another?
Create a snapshot of the instance
Create an image from the snapshot
Copy the image to the new region and create an instance.
What are the default and detailed monitoring times?
Default is 5 minutes
Detailed is 1 minute
Why do we only get a DNS name for a Load Balancer?
Because the underlying IP address could change.
What are the default settings for a security group?
All inbound traffic is blocked
All outbound traffic is allowed
What is Elastic Block Store (EBS)?
Allows you to attach storage volumes to EC2 instances
Can you block specific IP addresses in a security group?
No
What 4 Cloudwatch Metrics are provided by default?
CPU
Disk
Network
Status
What happens to an EBS volume after the EC2 instance its attached to is terminated?
It will be deleted. When creating the instance, “Delete on Termination” is selected by default
Are security groups stateful or stateless?
They are stateful. When you create an inbound rule, that traffic is automatically allowed back out.
How many Availability Zones can a placement group be deployed to?
One
What is the default setting for termination protection?
It is disabled
What are the 2 status checks for EC2 instances?
System Status Check
Instance Status Check
What does a System Status Check do?
Checks the status of the underlying architecture
What does an Instance Status Check do?
Checks that the OS can receive traffic
What was topping me from ssh’ing into an EC2 instance after I added the correct rule to the security group?
The Internet Gateway was not attached to the VPC.
What 2 volume types cannot be root volumes?
SC1 - Cold HDD
ST1 - Thhroughput Optimized HDD
What are the 3 types of boot volumes?
GP2 - General Purpose SSD
Io1 - Provisioned IOPS
Magnetic
Can I move a Reserved Instance from one region to another?
No
For Multiple Availability Fault Tolerance, how can you ensure 100% of required servers are online?
Always assume the Availability Zone with the most instances is the one to fail.
Are individual instances provisioned in regions or availability zones?
Availability Zones
What are the 11 EC2 instance types?
F - Field Programmable Gateway I - IOPS G - Graphics H - High Disk Throughput T - Cheap Genreal Purpose D - Density R - RAM M - Main option for Genral Purpose C - Compute P - Graphics (pics) X - Extreme Memory
What is Cloudwatch?
A monitoring service for your resources
What is Cloudtrail?
A service that provides tracking and auditing for actions taken in your environment
How many security groups can an instance have?
Multiple
What are the 3 steps to move an EC2 instance from one region to another?
Create a snapshot
Copy the snapshot to the new region
Create an image from the snapshot
