EC2 Basics: What is an Instance? Types and Pricing Models

Lesson Objectives

By the end of this lesson, you will:

1. Understand what an Amazon EC2 instance is and its role in cloud computing.
2. Learn about the different EC2 instance types and their use cases.
3. Explore EC2 pricing models and how to choose the best option for your workload.
4. Launch your first EC2 instance in a hands-on lab.

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Introduction: Your Virtual Machine in the Cloud

Imagine you’re setting up a new web application. Traditionally, you’d need to purchase a physical server, install operating systems, and manage hardware. This process is expensive, time-consuming, and inflexible.

With Amazon EC2 (Elastic Compute Cloud), you can skip all that. EC2 allows you to launch virtual servers, known as instances, in minutes. You can scale them up or down based on your needs, choose from a variety of configurations, and pay only for what you use.

In this chapter, we’ll explore the basics of EC2, understand its instance types, and look at pricing models to make the most cost-effective decisions.

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Step 1: What is an EC2 Instance?

An EC2 instance is a virtual server in the AWS cloud. Think of it as a resizable compute resource that you can configure with specific hardware and software to run your applications.

Why Do We Need Amazon EC2?

Amazon EC2 (Elastic Compute Cloud) provides scalable, on-demand compute resources that replace the need for physical servers. It’s essential for modern cloud computing because it offers flexibility, efficiency, and control over how applications run. Here’s why EC2 is a game-changer:

Why EC2?

1. Scalability: EC2 allows you to scale resources up or down based on demand, ensuring cost-effectiveness without compromising performance.
2. Flexibility: It supports various operating systems, configurations, and use cases, from hosting websites to running large-scale machine learning models.
3. On-Demand Availability: With EC2, you can launch instances within minutes, pay only for what you use, and terminate them when you’re done.
4. Global Reach: EC2 is available across AWS Regions, allowing you to deploy applications closer to your users for reduced latency.

What Can You Do with EC2?

• Host websites and web applications.
• Run backend servers for mobile or IoT applications.
• Process large-scale data and analytics workloads.
• Train and deploy machine learning models.
• Create test and development environments.
• Run containerized applications using Docker or Kubernetes.

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Step 2: EC2 Instance Types

EC2 instances are categorized based on their hardware capabilities and intended use cases.

1. General Purpose Instances

• Balanced compute, memory, and networking.
• Ideal for web servers, app development, and small databases.
• Examples:
  • t2.micro (Free Tier eligible): Great for low-traffic applications.
  • m5.large: Suitable for medium workloads.

2. Compute Optimized Instances

• High CPU performance for compute-intensive tasks.
• Ideal for gaming servers, data analysis, and batch processing.
• Example: c5.large.

3. Memory Optimized Instances

• High memory-to-CPU ratio for in-memory databases and big data.
• Example: r5.large.

4. Storage Optimized Instances

• High-speed storage for intensive read/write operations.
• Ideal for NoSQL databases and data warehouses.
• Example: i3.large.

5. GPU Instances

• Powerful GPUs for machine learning, 3D rendering, and high-performance computing.
• Example: p3.large.

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Step 3: EC2 Pricing Models

AWS offers multiple pricing options to fit your workload and budget.

1. On-Demand Instances

• Pay per second or hour without long-term commitments.
• Best for short-term, unpredictable workloads.
• Example: Testing a new application or running a development environment.

2. Reserved Instances

• Commit to a specific instance type for 1 or 3 years to save up to 75%.
• Best for steady-state or predictable workloads.
• Example: Hosting a long-running web application.

3. Spot Instances

• Use unused EC2 capacity at discounts of up to 90%.
• Best for flexible, non-critical workloads that can tolerate interruptions.
• Example: Running batch jobs or training machine learning models.

4. Savings Plans

• Flexible pricing model offering savings for consistent usage across EC2 and other compute services.
• Best for workloads that may vary across instance types or regions.

5. Dedicated Hosts

• Physical servers dedicated to your use for compliance or licensing requirements.
• Example: Running applications with strict regulatory requirements.

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Step 4: Deploying a PHP Website Using EC2

In this section, we’ll deploy a PHP website on an EC2 instance and make it publicly accessible. This hands-on guide assumes you already have an AWS account.

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Step 1: Launch an EC2 Instance

1. Log in to AWS: Go to the AWS Management Console and log in.
2. Navigate to EC2:
   • In the search bar, type EC2 and select it.
3. Launch Instance:
   • Click Launch Instance.
4. Choose an Amazon Machine Image (AMI):
   • Select Amazon Linux 2 AMI (Free Tier Eligible).
5. Select an Instance Type:
   • Choose t2.micro (Free Tier eligible).
6. Configure Instance Details:
   • Use default settings. Ensure the instance is in the default VPC.
7. Add Storage:
   • Leave the default storage size (8 GB).
8. Configure Security Group:
   • Create a new security group with the following rules:
     • HTTP (port 80): Allow from Anywhere (0.0.0.0/0, ::/0).
     • SSH (port 22): Allow from your IP (My IP).
9. Review and Launch:
   • Click Launch, select or create a key pair, and save the key file (.pem).

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Step 2: Connect to Your EC2 Instance

1. Find the Public IP:
   • In the EC2 dashboard, go to the Instances tab and copy your instance’s public IP address.
2. Connect via SSH:
   • Open a terminal or SSH client (like PuTTY on Windows).
   • Use the following command to connect (replace path-to-key.pem and public-ip):
     ssh -i "path-to-key.pem" ec2-user@public-ip


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Step 3: Install a Web Server and PHP

1. Update the System:
   • Run the following command:
     sudo yum update -y

2. Install Apache and PHP:
   • Install Apache:
     sudo yum install httpd -y

   • Install PHP:
     sudo amazon-linux-extras enable php8.0
sudo yum install php php-mysqlnd -y

3. Start and Enable Apache:
   • Start the Apache service:
     sudo systemctl start httpd

   • Enable Apache to start on boot:
     sudo systemctl enable httpd

4. Verify Apache Installation:
   • Open a browser and visit your instance’s public IP address. You should see the Apache default page.

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Step 4: Deploy Your PHP Website

1. Create a PHP File:
   • Navigate to the web server root directory:
     cd /var/www/html

   • Create a PHP file:
     sudo nano index.php

   • Add the following content to the file:
     <?php
echo "Welcome to my PHP website!";
?>

   • Save and exit (Ctrl + O, Enter, Ctrl + X).
2. Verify the Website:
   • Visit your instance’s public IP in a browser. You should see:
     Welcome to my PHP website!


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Step 5: Make Your Website Publicly Accessible

1. Check Security Group Rules:
   • Ensure that the security group associated with your instance allows HTTP (port 80) traffic from anywhere.
2. Test Public Access:
   • Open a browser and visit your instance’s public IP. The PHP website should load.

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Reflection: Why EC2 is Essential

In this lesson, you deployed a PHP website using an EC2 instance. Here’s why EC2 is vital:

1. Flexibility: You chose the operating system, installed the web server, and deployed custom code.
2. Scalability: As traffic grows, you can use Auto Scaling to add more instances.
3. Global Accessibility: By deploying in a specific region, your website can reach users with minimal latency.

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What’s Next?

In the next chapter, we’ll explore AWS Lambda, where you’ll learn how to run code without managing servers, introducing the concept of serverless computing.

Your EC2 journey has just begun—keep building and experimenting!