EC2 - Basics

Question 1

What is Amazon EC2?

Answer 1

• EC2 is one of the most popular AWS products
• EC2 = Elastic Compute Cloud = Infrastructure as a Service
• It mainly consists in the capability of:
  
  • Renting virtual machines (EC2)
  • Storing data on virtual drives (EBS)
  • Distributing load across machines (ELB)
  • Scaling the services using an auto-scaling group (ASG)
• Cost and Capacity Optimization - Pay for What You Use
• Knowing EC2 is fundamental to understand how the Cloud works

Question 2

What are EC2 sizing & configuration options?

Answer 2

Configuration how you want your EC2 Virtual instances to be:
* Operating System (OS): Linux, Windows or Mac OS
* How much compute power & cores (CPU)
* How much random-access memory (RAM)
* How much storage space:
* Network-attached (EBS & EFS)
* hardware (EC2 Instance Store - block-level storage physically attached to the host computer)
* Network card: speed of the card, Public IP address
* Firewall rules security group
* Bootstrap script (configure at first launch): EC2 User Data

Question 3

What is EC2 User Data?

Answer 3

• It is possible to bootstrap our instances using an EC2 User Data script
• Bootstrapping means launching commands when a machine starts
• That script is only run once when the instance starts
• EC2 User Data is used to automate boot tasks such as:
  
  • Install updates
  • Installing software
  • Downloading common files from the internet
  • Anything you can think of
• The EC2 User Data Script runs with the root user

Question 4

How do you launch a EC2 Instance?

Answer 4

1. Go to EC2 Dashboard
2. Click on Launch Instance
3. Enter instance name
4. Select the OS Image
   
   • Amazon Linux
   • macOS
   • Ubuntu
   • Windows
   • Red Hat
   • SUSE Linux
   • Debian
5. Select the OS machine image type
6. Select the machine architecture 64-bit (x86) or 64-bit(ARM)
7. Select instance type - t2.macro
8. Create SSH Key Pair to login to your EC2 Instance
9. Network section will create a VPC with an auto assign public IP
10. A default Security Group (firewall) will be automatically created called launch-wizard-1 with the following rules:
    
    • Allow SSH traffic from Anywhere 0.0.0.0/0
    • Allow HTTPs traffic from the internet
    • Allow HTTP traffic from the internet
11. Configure Storage - free tier can get up to 30 GB of EBS storage
    
    • Advanced option: Delete on termination is default to Yes meaning if we terminate our EC2 instance the storage volume will be deleted
12. Advnace Details:
    
    • Domain Active Directory (AD) creation
    • IAM instance profile
    • Hostname and DNS
    • Instance behavior settings
    • Metadata
    • User Data
13. Launch instance

Question 5

What are the methods to connect to your EC2 instance?

Answer 5

• SSH (OpenSSH - Mac, Linux, Windows > 10)
• Putty (Windows < 10)
• EC2 Instance Connect (web browser)

Question 6

What are the available AWS SSH Keys and formats?

Answer 6

Two type of SSH Keys:
1. RSA encryption
2. ED25519 encryption (not supported for Windows instances)

Two types of key file format:
1. .pem - use with OpenSSH (macOS, Linux, Windows 10+)
2. .ppk - use with PuTTY (Windows < 10)

Question 7

How do you create and connect to EC2 with SSH?

Answer 7

• Go to EC2 Dashboard > Key Pairs
• Click Create key pair to create a new key pair
• Download the .pem (OpenSSH) or .ppk (PuTTy)
• Open SSH client with command prompt
• Enter ssh -i "./EC2_Instance_SSH_Keys.pem" ec2-34-228-11-197.compute-1.amazonaws.com

Note: If you’re getting WARNING: UNPROTECTED PRIVATE KEY FILE! - remove all other user’s access to your SSH file

Question 8

What is the EC2 Instance Type naming convention?

Answer 8

AWS has the following naming convention:

• m5.2xlarge
  • m: instance class
  • 5: generation (AWS improves them over time)
  • 2xlarge: size within the instance class

Question 9

What are the EC2 Instance types?

Answer 9

Instance vCPU Mem (GiB) Storage Network Perf EBS Bandwidth (Mbps)
1. t2.micro 1 1 EBS-Only Low to Moderate
2. t2.xlarge 4 16 EBS-Only Moderate
3. c5d.4xlarge 16 32 1 x 400 NVMe SSD Up to 10 Gbps 4,750
4. m5.8xlarge 32 128 EBS-Only 10 Gbps 6,800
5. r5.16xlarge 64 512 EBS-Only 20 Gbps 13,600

t2.micro is part of the AWS free tier (up to 750 hours per month)

Question 10

How are EC2 optimized for different use case?

Answer 10

• Different types of EC2 instances optimized for different use cases:
  
  • General Purpose
  • Compute Optimized
  • Memory Optimized
  • Accellerated Computing
  • Storage Optimized
  • HPC Optimized
  • Instance Features
  • Measuring Instance Performance