AWS Cheat Sheets - Compute Services - EC2 Dojo

Question 1

What is EC2?

Answer 1

A Linux/Windows/Mac based virtual server that you can provision

Question 2

AWS Ntro System

Answer 2

This is the underlying platform of the next generation of EC2 instances.

Traditionally, hypervisors protect the physical hardware and BIOS, virtualize the CPU, storage, networking and provide a rich set of management capabilities.

With the Nitro System, these functions are offloaded to dedicated hardware and software, thereby reducing costs of your instances in the process.

Hence, the Nitro Hypervisor delivers performance that is indistinguishable from bare metal and performs better than its predecessors

Question 3

Host Recovery fro Amazon EC2

Answer 3

This automatically restarts your instances on a new host in the event of an unexpected hawardware failure on a Dedicated Host

Question 4

EC2 Hibernation

Answer 4

This is available for On Demand and Reserved Instances running on freshly launched instances running Amazon Linux and Ubuntu.
You can enable hibernation for your EBS backed instances at launch.

You can then hibernate and resume your instances through the AWS Management Console or through the AWS SDK and CLI using the existing stop instances and start instances commands

Hibernation requires an EC2 instance to be an encrypted EBS backed instance

Question 5

EC2 Instance States

Answer 5

Start - run your instance normally. You are continuously billed when your instance is running

Stop - This is just a normal shutdown. You may restart it again anytime. All EBS volumes remain attached, but data in instance store volumes are deleted. You wont be charged for usage while instance is stopped. You can attach or detach EBS volumes.You can also create an AMI from the instance, and change the kernel, RAM disk, and instance type while in this state

Hibernate - When an instance is hibernated, it writes the in memory state to a file in the root EBS volume and then shuts itself down. The AMI used to launch the instance must be encrypted, and also the root EBS volume of the instance. The encryption ensures proper protection for sensitive data when it is copied from memory to the EBS volume. While the instance is in hibernation, you pay only for the EBS volumes and Elastic IP Addresses attached to it; there are no hourly charges

Terminate - Instance performs a normal shutdown and gets deleted. You wont be able to restart an instance once you terminate it. The root device volume is deleted by default, but any attached EBS volumes are preserved by default. Data in instance store volumes are deleted. You can prevent accidental termination by enabling termination protection

Question 6

Root Device Volumes

Answer 6

The root device volume contains the image used to boot the instance

Question 7

Instance Store Backed Instances

Answer 7

Any data on the instance store volumes is deleted when the instance is terminated (instance store backed instances do not support the Stop action) or if it fails (such as if an underlying drive has issues)

You should also back up critical data from your instance store volumes to persistent storage on a regular basis

Question 8

Amazon EBS Backed Instances

Answer 8

An Amazon EBS backed instance can be stopped and later restarted without affecting data stored in the attached volumes

When in a stopped state, you can modify the properties of the instance, change its size, or update the kernel it is using, or you can attach your root volume to a different running instance for debugging or any other purpose

By default the root device volume for an AMI backed by Amazon EBS is deleted when the instance terminates

Previously, to launch an encrypted EBS backed EC2 instance from an unencrypted AMI, you would first need to create an encrypted copy of the AMI and use that to launch the EC2 instance. Now you can launch encrypted EBS backed EC2 instances from unencrypted AMIs directly

Question 9

Amazon Machine Image (AMI)

Answer 9

This is a template for the root volume for the instance (OS, application server and applications)

Launch permissions that control which AWS accounts can use the AMI to launch instances

A block device mapping that specifies the volumes to attach to the instance when it is launched

You can copy AMIs to different regions

Question 10

EC2 Pricing

Answer 10

On Demand - pay for the instances that you use by the second, with no long term commitments or upfront payments

Reserved - Make a low, one time, up front payment for an instance, reserve it for a one or three year term, and pay a significantly lower hourly rate for these instance. It has two offering classes: Standard and Convertible

The Standard Class provides the most significant discount but you can only modify some of its attributes during the term. It can also be sold in the Reserved Instance Marketplace

The Convertible Class provides a lower discount than Standard Reserved Instances, but can be exchanged for another Convertible Reserved Instance with different instance attributes. However this one cannot be sold in the Reserved Instance Marketplace

Spot - request unused EC2 instances, which can lower your costs significantly. Spot Instances are available at up to a 90% discount compared to On Demand.

Question 11

Spot Fleet

Answer 11

This is a collection of Spot instances and optionally On Demand Instances. The service attempts to launch the number of Spot Instances and On Demand Instances to meet your specified target capacity. The request for Spot Instances is fulfilled if there is available capacity and the maximum price you specified in the request exceeds the current spot price. The Spot Fleet also attempts to maintain its target capacity fleet if your Spot Instances are interrupted

Question 12

Spot Capacity Pool

Answer 12

This is a set of unused EC2 instances with the same instance type, OS, Availability Zone and network platform.

You can start and stop your Spot Instances backed by Amazon EBS at will.

You can modify instance types and weights for a running EC2 Fleet or Spot Fleet without having to recreate it

Question 13

EC2 Security

Answer 13

Use IAM to control access to your instances with IAM Policies and IAM roles

Restrict access by only allowing trusted hosts or networks to access ports on your instance

Question 14

Security Group

Answer 14

Acts as a virtual firewall that controls the traffic for one or more instances.

You can create different security groups to deal with instances that have different security requirements

You can add rules to each security group that allow traffic to or from its associated instances

You can modify the rules for a security group at any time

New rules are automatically applied to all instances that are associated with the security group

Evaluates all the rules from all the security groups that are associated with an instance to decide whether to allow traffic or not

By default, security groups allow all outbound traffic

Security Groups rules are always permissive; you cant create rules that deny access

Security groups are stateful

Question 15

Elastic IP Address

Answer 15

This is a static IPv4 address designed for dynamic cloud computing
With it, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account.

If you have not enabled auto assign public IP address for your instance, you need to associate an Elastic IP address with your instance to enable communication with the Internet

An Elastic IP address is for use in a specific region only

By default, all AWS accounts are limited to 5 Elastic IP addresses per region, because public internet addresses are a scarce public resource

Question 16

Elastic Network Interface

Answer 16

This is a logical networking component in a VPC that represents a virtual network card, which directs traffic to your instance

Question 17

Primary Network Interface

Answer 17

Every instance in a VPC has a default network interface, called the primary network interface (eth0)

You cannot detach a primary network interface from an instance

You can create and attach additional network interfaces. The maximum number of network interfaces that you can use varies by instance type

You can attach a network interface to an instance in a different subnet as long as its within the same AZ

Default interfaces are terminated with instance termination

Question 18

EC2 Scaling Groups

Answer 18

These distribute traffic among instances using Elastic Load Balancer

This contains a collection of EC2 instances that are treated as a logical grouping for the purposes of automatic scaling and management

An Auto Scaling group also lets you use Amazon EC2 Auto Scaling features such as health check replacement and scaling policies

Question 19

Bastion Host

Answer 19

This is a server whose purpose is to provide access to a private network from an external network such as the internet using SSH or RDP protocols

Question 20

Enhanced Networking

Answer 20

It provides higher bandwidth, higher packet per second performance and consistent lower inter instance latencies, which is being used in Placement Groups

It uses single root I/O virtualization to provide high performance networking capabilities.

Single Root IO virtualization is a method of device virtualization that provides higher IO performance and lower CPU utilization when compared to traditional virtualized network interfaces

Question 21

Elastic Fiber Adapter (EFA)

Answer 21

This is a network device that you can attach to your EC2 instance to significantly accelerate machine learning applications and High Performance Computing (HPC)