EC2

Amazon Elastic Compute Cloud (EC2) 筆記。

Sizing & Configuration Options

• OS: Linux, Windows, MacOS
• CPU, RAM
• Storage Space:
  • Network-attached (EBS, EFS)
  • Hardware (EC2 Instance Store)
• Network card: Speed of the card, Public IP address
• Firewall rules: Security group
• Bootstrap script: EC2 User Data Script (configure at first launch)

User Data Script

• Runs with root user
• Automate boot tasks:
  • Installing updates
  • Installing software
  • Downloading common files from the internet

#!/bin/bash
## Use this for your user data (script from top to bottom)
## install httpd (Linux 2 version)
yum update -y
yum install -y httpd
systemctl start httpd
systemctl enable httpd
echo "<h1>Hello World from $(hostname -f)</h1>" > /var/www/html/index.html

Instance Types

C - Compute Optimized

Great for compute-intensive tasks:

• Batch Processing workloads
• Media transcoding
• High performance web servers
• Gaming Servers

R - Memory Optimized

Fast performance for workloads:

• High performance RDB or non-RDB
• Distributed web scale cache stores
• In-memory db optimized for BI
• Real-time processing of big unstructured data

I, G, H - Storage Optimized

Great for storage-intensive tasks that require high, sequential read and write access:

• High frequency OLTP systems
• Relational & NoSQL databases
• Cache for in-memory databases
• Data warehousing applications
• Distributed file systems

Security Groups

Acting as a firewall on EC2 instances. Regulate:

• Access to Ports
• Authorized IP ranges - IPv4 & IPv6
• Control of inbound network (from other to the instance)
• Control of outbound network (from the instance to other)

Good to Know

• SG can be attached to multiple instances
• Locked down to a region/VPC combination
• Lives outside the EC2 - if traffic is blocked, EC2 instance won’t see it
• Good to maintain one separate security group for SSH access
• If your application:
  • Is not accessible (time out) → Security group issue
  • Gives connection refused error → Application error or not launched
• All inbound traffic is blocked by default
• All outbound traffic is authorized by default

Ports

SSH into EC2 Instance

Linux / Mac OS X

chmod 0400 EC2Tutorial.pem
ssh -i EC2Tutorial.pem ec2-user@54.95.249.238

Windows 10

ssh -i .\EC2Tutorial.pem ec2-user@54.95.249.238

EC2 Instance IAM Roles

Navigate: Instances → Actions → Security → Modify IAM role

Purchase Options

Spot Instances Use Cases

Useful for workloads resilient to failure:

• Batch Jobs
• Data Analysis
• Image Processing
• Distributed workloads
• Flexible start/end time workloads

Ways of Accessing EC2

1. Open port 22 and use SSH keys
2. Use EC2 Instance Connect (still requires port 22)
3. Use Session Manager (needs IAM Role: AmazonSSMManagedInstanceCore)

AMI (Amazon Machine Image)

• Customization of an EC2 instance
• Built for a specific region (can be copied across regions)
• Can launch EC2 instances from:
  • Public AMI (AWS provided)
  • Your own AMI
  • AWS Marketplace AMI

Instance Store

• High-performance hardware disk attached to EC2
• Better I/O performance
• Data is lost if instance is stopped/terminated
• Good for buffer, cache, scratch data, temporary content