Introduction to EC2

Amazon EC2 (Elastic Compute Cloud) is a service from AWS (Amazon Web Services) that lets you run virtual servers, known as instances, in the cloud. Unlike traditional IT setups where companies have to buy, manage, and upgrade physical servers, EC2 allows you to quickly get the computing power you need without the hassle of hardware. EC2 is flexible, so you can scale up or down depending on your needs, making it cost-effective. Whether you're running a small app or a large system, EC2 lets you use AWS's secure and reliable global infrastructure, reducing the complexity of managing your own servers.

For example, imagine an online store that gets a lot of traffic during holiday sales, like Black Friday. Traditionally, they would have to buy extra servers just to handle this short-term traffic spike, which can be expensive and wasteful. With EC2, they can simply add more virtual servers when they expect high traffic and reduce them once the sale is over. This means they only pay for what they use, saving money and ensuring the website can handle all the visitors without crashing.

Types of EC2 Instances

EC2 offers several types of instances to match different kinds of workloads. Instead of a one-size-fits-all approach, you can choose the instance type that best fits the specific needs of your application, whether you need more computing power, memory, or storage. Let’s break down the main types of EC2 instances:

General Purpose
General Purpose instances provide a balanced mix of compute, memory, and networking. They are ideal for a wide range of tasks that don't require a lot of any one resource but need a good balance of all three. These are perfect for running web servers, small databases, or development environments.

Example: If you're hosting a personal blog or a small website with moderate traffic, a General Purpose instance like the t3.micro would be a cost-effective option that provides all the necessary resources.
Memory Optimized
Memory Optimized instances are designed for applications that require a lot of memory (RAM). These instances are great for tasks like large-scale databases or real-time data processing, where high memory availability is crucial for performance.

Example: If you're using an in-memory database like Redis or running analytics software that processes large datasets in real-time, a Memory Optimized instance such as r5.large would be ideal.
Compute Optimized
Compute Optimized instances are built for applications that need high-performance processing power. These instances excel in tasks like scientific modeling, gaming servers, or machine learning, where the CPU needs to handle a lot of calculations quickly.

Example: If you’re running a machine learning algorithm, a gaming server, or performing heavy data computations, a Compute Optimized instance like c5.large will offer the processing power you need for smooth performance.
Storage Optimized
Storage Optimized instances are made for tasks that require fast, high-capacity storage. They are best for applications that need quick read and write speeds with large datasets, like data warehouses or big data analytics.

Example: If you’re managing a big data application or a database that requires quick access to large files, a Storage Optimized instance such as i3.large would give you the high-speed storage performance you need.

Choosing the right EC2 instance type helps ensure your applications run smoothly and efficiently, allowing you to balance performance with cost depending on your workload.

EC2 Purchasing Options

AWS offers different ways to pay for EC2 instances to help you manage costs based on how you use them. Here’s a simple breakdown of each purchasing option:

On-Demand Instances
What It Is: Pay for compute power by the hour or second.
Best For: Short-term or unpredictable workloads.
Example: Testing a new app or running a small, temporary project.
Reserved Instances
What It Is: Commit to using EC2 for 1 or 3 years to get up to 75% off the regular price.
Best For: Long-term, steady workloads where you need consistent capacity.
Example: Hosting a website with steady traffic that runs all year round.
Savings Plans
What It Is: Commit to a fixed amount of usage (dollars per hour) for 1 or 3 years to get up to 72% off.
Best For: Flexible workloads where you want to save money without being tied to a specific instance type or region.
Example: Running various applications across different regions but looking for overall cost savings.
Spot Instances
What It Is: Bid on unused EC2 capacity at a lower price—up to 90% off regular prices.
Best For: Flexible, non-essential tasks that can handle interruptions.
Example: Running large data processing jobs or batch processing that can be stopped and started as needed.
Dedicated Hosts
What It Is: Reserve physical servers just for your use, giving you control over the hardware.
Best For: Applications with strict compliance or licensing needs.
Example: Running software that requires specific hardware or has licensing restrictions.
Dedicated Instances
What It Is: Use EC2 instances on hardware that is dedicated to only your account, but AWS manages the server placement.
Best For: Secure applications needing hardware isolation.
Example: Handling sensitive data where you need extra security but don't need full control over the physical server.
Capacity Reservations
What It Is: Reserve EC2 capacity in a specific location to ensure it’s available when you need it.
Best For: Critical applications where you need guaranteed access to resources.
Example: Preparing for a major event where you need to ensure enough server capacity is available.

Each option helps you tailor your EC2 usage to fit your needs and budget, whether you need flexibility, cost savings, or guaranteed resources.

Project: Creating a Web Application Using EC2 Instances: A Beginner's Guide

In this guide, we’ll walk through the process of setting up a simple web application on an AWS EC2 instance. By the end, you’ll have a basic web page up and running that says “Hello World!” Let’s dive in!

Launch an EC2 Instance
- Sign In to AWS Management Console:
  Go to the AWS Management Console and log in with your credentials.
- Navigate to EC2 Dashboard:
  Find and select EC2 from the list of services.
- Launch a New EC2 Instance:
  Click “Launch Instance”.
  - Choose an Amazon Machine Image (AMI). For simplicity, select an Ubuntu or Amazon Linux AMI.
  - Select an Instance Type. The t2.micro type is a good start as it's eligible for the free tier.
  - Click “Next: Configure Instance” to proceed.
- Configure Security Group:
  Ensure your security group allows traffic on port 80 (HTTP) and port 22 (SSH) for remote access. This is crucial for allowing web traffic and SSH connections to your instance.
- Review and Launch:
  Select a key pair for SSH access. If you don’t have one, create a new key pair and download the .pem file. Click “Launch” to start your instance.
Connect to Your EC2 Instance Using MobaXterm

MobaXterm is a popular SSH client that helps you connect to your EC2 instance.
- Open MobaXterm:
  Launch the MobaXterm application.
- Create a New SSH Session:
  Click on “Session” and choose “SSH”. Enter the public IP of your EC2 instance in the “Remote host” field. Select “Use private key” and browse to your .pem file.
- Connect:
  Click “OK”.

Problems and Solutions:

Authentication Issues: If you encounter errors like "No supported authentication methods available" or "Server refused our key", ensure the .pem file permissions are set correctly (chmod 400 /path/to/your-key.pem) and verify that the correct .pem file matches the key pair for your instance.

Install and Set Up a Web Server

Depending on your Linux distribution, you’ll need different commands to install Apache (a popular web server).

Identify Your Distribution:
Run the following command to find out which Linux distribution you are using:
```
  cat /etc/*release
```

Install Apache:

For Ubuntu/Debian:

  sudo apt-get update
  sudo apt-get install -y apache2
  sudo systemctl start apache2
  sudo systemctl enable apache2

For Amazon Linux 2/CentOS/RHEL:

  sudo dnf update -y
  sudo dnf install -y httpd
  sudo systemctl start httpd
  sudo systemctl enable httpd

Verify Installation:
Check the status of Apache:

  sudo systemctl status apache2   # For Ubuntu/Debian
  sudo systemctl status httpd     # For Amazon Linux/CentOS/RHEL

Problems and Solutions:

Command Not Found: If you see "sudo: yum: command not found", verify your Linux distribution and use the appropriate package manager commands (apt-get for Ubuntu/Debian, dnf for Amazon Linux/CentOS/RHEL).
Web Server Not Starting: If you receive errors like "Unit httpd.service could not be found", ensure that you have installed the web server correctly and use the correct service name.

Deploy Your Web Application
- Create Your Web Page:
  Navigate to the web server's root directory:
```
  cd /var/www/html
```
  Create a new file named index.html:
```
  sudo nano index.html
```
  Add the following content:
```
  <!DOCTYPE html>
  <html>
  <head>
      <title>Hello World</title>
  </head>
  <body>
      <h1>Hello World!</h1>
  </body>
  </html>
```
  Save and exit the file.
- Check Your Web Application:
  Open your web browser and enter the public IP address of your EC2 instance. You should see the “Hello World!” message displayed.

Problems and Solutions:

Access Denied: If you get a "403 Forbidden" error, check the file permissions and ensure the Apache web server has read access to the file.
Page Not Found: Verify that you are accessing the correct public IP address and that Apache is running.

Cleanup

To avoid incurring additional charges, make sure to terminate your EC2 instance once you have finished your project. Here’s how:
- Go to the EC2 Dashboard:
  Navigate to the EC2 dashboard in the AWS Management Console.
- Select Your Instance:
  Find and select the instance you want to terminate from the list.
- Terminate the Instance:
  Click on the “Instance State” dropdown menu and choose “Terminate Instance.” Confirm the termination when prompted.

By terminating your instance, you ensure that you won’t be charged for any unused resources. If you have any snapshots or volumes you no longer need, consider cleaning those up as well to avoid additional costs.

In conclusion, Amazon EC2 offers a versatile and scalable solution for running virtual servers in the cloud, making it an excellent choice for businesses of all sizes. By understanding the different types of EC2 instances and their specific use cases, you can optimize performance and cost for your applications. Additionally, the various purchasing options provide flexibility in managing expenses based on your workload requirements. Setting up a web application on an EC2 instance is straightforward, and with the step-by-step guide provided, even beginners can get started quickly. As you gain more experience, you can explore advanced configurations and leverage the full potential of AWS EC2 to meet your evolving needs. Happy building!

Amazon EC2 for Beginners: Understanding Instances, Pricing, and Web Application Setup

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Kajal Patil

Kajal Patil