AWS EC2 Basics: Core Concepts Explained

published on 01 January 2024

As software engineers know, leveraging cloud infrastructure can be incredibly valuable, yet the learning curve for core services like EC2 can seem daunting.

This post breaks down the key concepts around AWS EC2 in simple terms, so you can quickly grasp the fundamentals.

You'll learn exactly what EC2 is, the main components and services, how to launch instances, choose the right configurations, manage costs effectively, and scale workloads efficiently in AWS.

Introduction to AWS EC2 Basics for Software Engineers

Amazon Elastic Compute Cloud (EC2) is a foundational AWS service that provides secure, resizable compute capacity in the cloud. As software engineers, understanding the basics of EC2 enables us to leverage the flexibility and scalability of cloud infrastructure.

Understanding Amazon Elastic Compute Cloud (EC2)

EC2 stands for Elastic Compute Cloud. It is one of the core AWS services that forms the backbone of many cloud-based solutions.

Some key things to know about EC2:

  • EC2 provides virtual machine instances that can run a variety of operating systems and software. These are called EC2 instances.

  • You only pay for the compute time you use. There is no long-term commitment or upfront cost.

  • EC2 enables engineers to quickly scale up or down based on application demand. More instances can be launched automatically if traffic spikes.

  • There is a wide variety of instance types optimized for different performance needs like CPU, memory, storage, or GPU.

By leveraging EC2, engineers can deploy scalable and high-performing architecture without managing physical servers.

Amazon EC2 Features and Advantages

Some of the main features and advantages of Amazon EC2 include:

  • Scalable compute power - Launch as many or as few virtual servers as you need. Scale seamlessly to handle traffic spikes and new projects.

  • Choice of instance types - Optimized types for different workloads like general purpose, compute optimized, memory optimized, storage optimized, and accelerated computing.

  • Flexible pricing models - Pay only for what you use with no long-term commitments. Free Tier offers new users free EC2 usage every month.

  • Integrated security - IAM roles and security groups to restrict access. Options like encrypted storage and Dedicated Hosts.

  • Reliable - Amazon EC2 provides high reliability with multiple Availability Zones. Recover quickly from outages.

  • Managed service - AWS handles infrastructure maintenance and high availability. Engineers focus on deployment.

Practical Use Cases for EC2 Instances

EC2 can be used for a wide variety of workloads. Some examples include:

  • Hosting web applications and APIs
  • Running data processing jobs
  • Building continuous integration/continuous deployment (CI/CD) pipelines
  • Deploying microservices architecture
  • Setting up development, test, and production environments
  • Running compute-intensive simulations, machine learning models, and analytics

The elasticity and pay-as-you-go model make EC2 a versatile solution for software engineers. Integrations with other AWS services also enable engineers to build complete cloud-native applications.

What is EC2 and basics?

Amazon Elastic Compute Cloud (Amazon EC2) provides scalable computing capacity in the Amazon Web Services (AWS) cloud. EC2 allows you to launch as many or as few virtual servers as you need, configure security and networking, and manage storage.

Some key basics of EC2 include:

  • Instances - An EC2 instance is a virtual server in the AWS cloud. You can launch different instance types optimized for different use cases.
  • AMIs - An Amazon Machine Image (AMI) is a template that contains a software configuration for your EC2 instance. It serves as the basic building block for instances.
  • Pricing Models - You pay only for the compute capacity you actually use. Pricing is per second, with no long term contracts or upfront payments.

For software engineers, EC2 provides an easy way to deploy applications without worrying about infrastructure. You can quickly scale capacity up or down based on demand. Overall, EC2 eliminates the overhead of maintaining physical servers, while still giving you full control over your virtual computing environments.

Some key benefits of EC2 for developers include:

  • Fast provisioning of development and test environments
  • Dynamic scaling to meet changing traffic patterns
  • Pay-as-you-go pricing to optimize costs
  • Integration with developer tools and pipelines

By leveraging EC2, engineers can focus on building great applications rather than maintaining infrastructure. EC2's APIs and tooling make it simple to programmatically manage hundreds of instances.

What are the 3 types of EC2?

AWS EC2 offers a wide variety of instance types optimized for different use cases. At a high level, EC2 instances can be grouped into 3 main categories:

General Purpose Instances

General purpose instances provide a balance of compute, memory, and networking resources. They are a good choice for a variety of workloads such as web servers, code repositories, development environments, and small-scale production applications. Some popular general purpose instance types include:

  • T2/T3 - Burstable instance types ideal for workloads with varying performance needs. Provides a baseline level of CPU performance with the ability to burst above the baseline.
  • M5 - The latest generation of general purpose instances powered by 2.5 GHz Intel Xeon Platinum 8000 series processors. Offers a balance of compute, memory, and networking.

Compute Optimized Instances

Compute optimized instances are designed to deliver high performance for compute-intensive workloads. They provide more CPU power relative to memory and are well suited for batch processing jobs, media transcoding, high performance web servers, machine learning inference, ad serving, and dedicated gaming servers. Some examples include:

  • C5 - The latest generation of compute optimized instances featuring 3.0 GHz Intel Xeon Platinum 8000 series processors.

Memory Optimized Instances

Memory optimized instances are designed to deliver fast performance for memory-intensive workloads. They provide more memory relative to compute capabilities and are ideal for high performance databases, distributed web scale cache stores, real-time big data analytics, and other enterprise applications. Some popular memory optimized instance families include:

  • R5 - The latest generation of memory optimized instances powered by 3.1 GHz Intel Xeon Platinum 8000 series processors.
  • X1 - Provide one of the highest memory configurations optimized for large in-memory databases and enterprise SAP applications.

By understanding these 3 categories of EC2 instances, software engineers can select the right instance type based on their application performance, scale, and cost requirements. The key is matching workload profiles to the appropriate instance family and size.

What are the 7 steps to create a EC2 instance?

Creating an Amazon EC2 instance allows you to leverage AWS's compute infrastructure to run applications and services. Here are the key steps software engineers should follow:

Step 1: Sign in to the AWS Management Console

  • Navigate to the EC2 dashboard in the AWS Console. This is where you can manage EC2 instances.

Step 2: Choose a name for your instance

  • Give your instance a descriptive name to easily identify it later.

Step 3: Select an Amazon Machine Image (AMI)

  • AMIs function as templates for EC2 instances. Choose one with your preferred OS like Amazon Linux or Ubuntu.

Step 4: Choose an Instance Type

  • Instance type determines the hardware configuration like CPU, memory, storage. Common options are t2.micro or t3.medium.

Step 5: Create a Key Pair

  • Key pairs allow you to securely SSH into your instance. Create one and download the private key.

Step 6: Configure a Security Group

  • Security groups act as a virtual firewall, controlling traffic. Add rules to allow connections on port 22 for SSH.

Step 7: Add Storage

  • Default storage is usually sufficient but you can add more EBS volumes if needed.

Step 8: Review and Launch

  • Double check all settings then launch! You can now connect and start using your EC2 instance.

What is an AWS EC2 instance?

An Amazon EC2 instance is a virtual server running in the AWS cloud. It allows you to rent compute capacity and run applications on demand without managing physical servers.

Some key things to know about EC2 instances:

  • Flexible Configurations: You can configure EC2 instances to meet your specific needs in terms of CPU, memory, storage, and networking. There are many instance types optimized for different use cases.

  • Scalable: You can launch as many instances as you need and scale up or down to meet changing demands. This makes EC2 very cost-effective.

  • Secure: EC2 instances run on highly secure AWS infrastructure. You control network access via security groups and can encrypt sensitive data.

  • Managed: AWS handles all the infrastructure maintenance like hardware failures and software updates. You just focus on your applications.

  • Pay-As-You-Go: You pay for the instances you launch on an hourly basis with no long-term commitments. This reduces costs and risks.

In summary, EC2 instances are the fundamental compute building blocks that allow you to leverage the flexibility and scalability of AWS. By launching instances tailored to your apps, you can deploy solutions faster and scale seamlessly.


Setting Up Your EC2 Environment

Creating and configuring an Amazon EC2 instance is the first step to leveraging AWS compute services. This section will guide software engineers through the key steps of setting up an EC2 environment using the AWS Console and AWS CLI.

Creating an AWS Account for EC2 Access

To get started with Amazon EC2, you'll need an AWS account. Here's a quick guide to signing up:

  • Go to and click Create an AWS Account.
  • Follow the on-screen instructions to sign-up for a free-tier eligible account. This allows you to access certain AWS services like EC2 for free under usage limits.
  • Enter your account details and credit card information. Your card will only be charged if you exceed the free-tier limits.
  • Once your account is created, you can access the AWS Console and EC2 dashboard.

How to Create an EC2 Instance in AWS Step by Step

Follow these steps to launch your first EC2 Linux instance using the AWS Console:

  1. In the AWS Console, navigate to the EC2 dashboard under Compute.
  2. Click Launch Instance to start the wizard.
  3. Select an Amazon Machine Image (AMI) that has Linux installed. Common options are Amazon Linux 2 or Ubuntu.
  4. Choose an instance type such as t2.micro which is free-tier eligible.
  5. Configure the instance details if needed, or keep the defaults.
  6. Add storage by modifying the volume size or adding new volumes.
  7. Tag your instance with a name to identify it.
  8. Configure a security group with allowed ports and IP addresses.
  9. Review your settings then click Launch Instance.
  10. Create or upload an SSH key pair to access the instance securely.
  11. Once launched, view your instance on the EC2 dashboard.

When selecting an AMI, instance type, and storage, consider factors like performance needs and cost to find the right balance.

AWS EC2 Login and Instance Connection Methods

There are a couple ways to connect to your EC2 instance:

  • EC2 Instance Connect - A simple browser-based SSH connection using SSL certificates.
  • AWS Systems Manager Session Manager - Start an interactive shell or run commands on your instance through SSM.

Both avoid needing to open SSH ports publicly or manage key pairs.

Instance Connect is good for quick access while SSM can automate tasks across fleets of instances.

Launching Instances with AWS CLI

You can also launch EC2 instances using the AWS Command Line Interface:

aws ec2 run-instances --image-id ami-0abcdef1234 --count 1 --instance-type t2.micro --key-name MyKeyPair

This will:

  • Launch 1 t2.micro instance
  • Use the specified AMI
  • Assign a key pair for SSH access

You need to create key pairs, VPCs, and security groups first before launching instances with the CLI.

This covers the basics of getting started with EC2. With your environment configured, you can now deploy workloads on flexible and scalable compute capacity in the AWS cloud.

Understanding EC2 Core Components

Amazon Elastic Compute Cloud (EC2) provides scalable computing capacity in the AWS cloud. As a software engineer, understanding the core components of EC2 is key to efficiently utilizing its resources.

Types of EC2 Instances and Their Uses

There are many types of EC2 instances optimized for different use cases. A few key ones include:

  • t2.micro - Free tier eligible general purpose instance for basic workloads. Often used for testing and development.
  • m5.large - General purpose instance balanced for cost and performance. Good for web servers and small databases.
  • c5.xlarge - Compute optimized high performance instance for CPU intensive workloads like batch processing.

When launching an EC2 instance, it's important to select the right instance type based on your application's compute, memory, storage, and networking requirements.

Amazon Machine Images (AMIs): The Quickstart to EC2

AMIs contain a pre-configured operating system, software, and settings to quickly launch EC2 instances. Rather than configuring instances from scratch, engineers can launch from ready-made AMIs to save time.

Key benefits include:

  • Launch instances faster with pre-installed software
  • Quickly scale to hundreds of instances using the same AMI
  • AMI baking helps enforce organizational standards

It's best practice to create custom AMIs tuned to your applications for rapid deployment.

Securing EC2 Instances with Security Groups

Security groups act as virtual firewalls to control inbound and outbound traffic to EC2 instances. Key capabilities:

  • Set custom TCP/UDP rules for access
  • Reference by instance or IP address
  • Stateful so return traffic is automatically allowed

Properly configuring security groups is vital for governing access to sensitive instances.

Amazon EC2 Auto Scaling and Elastic Load Balancing

To ensure high availability under changing load patterns:

  • Auto Scaling: Automatically adds or removes EC2 instances based on demand
  • Elastic Load Balancing: Distributes incoming traffic across multiple instances

Combining these services provides fault tolerance and flexible scaling to meet application needs.

Understanding these core components allows software engineers to unlock the full potential of Amazon EC2. Proper instance selection, AMI configuration, security group rules, and auto scaling policies are key to effectively running applications on EC2.

EC2 Storage Solutions and Management

EC2 offers a range of storage options to cater to different data persistence requirements and performance needs.

Using EBS Volumes for Durable EC2 Storage

Elastic Block Store (EBS) provides durable and persistent block-level storage volumes for EC2 instances. Attaching EBS volumes allows you to scale storage independently, persist data beyond the lifetime of an instance, and achieve higher levels of availability and durability.

To get started with EBS, you first create a volume of your desired size and performance characteristics. Volumes can range from 1 GiB up to 16 TiB. You can choose between magnetic HDD-backed volumes (st1, sc1), general purpose SSD (gp2, gp3) or provisioned IOPS SSD (io1, io2) depending on your performance needs.

Once created, EBS volumes can be attached to an EC2 instance to provide storage for that instance. The process works as follows:

  1. Create an EBS volume in the same Availability Zone as your instance
  2. Attach the volume to your instance (can be done via AWS Console or CLI)
  3. The attached volume will appear as a block device in your instance
  4. Format the volume with a filesystem and mount to start using

Key benefits of using EBS include:

  • Persistence - Data persists independently from the lifecycle of your EC2 instance
  • Availability - Volumes can be detached and re-attached to other instances
  • Durability - Replicated within an Availability Zone for high durability
  • Flexibility - Dynamically increase volume size or adjust performance

Overall, EBS volumes provide a highly durable, available and flexible storage option for EC2 workloads requiring data persistence.

Temporary Storage with EC2 Instance Store

In contrast to EBS volumes, EC2 Instance Store provides temporary block-level storage directly attached to the physical host of your EC2 instance. Instance store is ideal for temporary storage of information that changes frequently, such as buffers, caches, scratch data and other temporary content.

The data in instance store persists only during the lifecycle of your EC2 instance. Once your instance is stopped or terminated, any data on instance store volumes is lost.

Benefits of using instance store include:

  • High performance - Up to 10x faster than EBS in some instance types
  • Temporary storage - Useful for buffers, caches, scratch data
  • Included - Available by default with some instance types

Instance store is well-suited for large scale, read-heavy workloads that require high, consistent I/O performance like MapReduce and big data processing. It's also useful for buffering data before batch uploading to durable storage.

Choosing the Right Storage Option for Your Workload

When deciding between EBS and instance store, consider factors like persistence requirements, performance needs and instance compatibility:

  • EBS provides durable, resizable storage independent of an EC2 instance. Use EBS for data that must persist longer than the lifecycle of a single instance.

  • Instance store offers high performance temporary storage directly attached to the physical host. Use instance store for data that can be easily reproduced or does not need long-term persistence.

  • Check instance type details to confirm compatibility with EBS or instance store before launching. Some instance families like T2 do not support instance store volumes.

Evaluating the differences between EBS and instance store will help guide you to the right storage solution based on the performance, persistence and access patterns required by your specific workload.

Managing Costs with AWS EC2 Pricing Models

Understanding the various EC2 pricing models available can help software engineers optimize cloud costs when building applications. This section covers key pricing concepts and strategies.

Understanding EC2 Instance Types and Pricing Options

EC2 offers a wide variety of instance types optimized for different use cases. It's important to select the right instance type to avoid overspending:

  • General purpose instances like T3 provide balanced CPU, memory, and networking for most applications. Often the most cost-effective option.
  • Compute optimized instances like C5 provide more CPU power for high performance computing apps. Tend to be more expensive.
  • Memory optimized R5 instances provide more RAM for memory-intensive apps like databases. Also carry a price premium.

In addition, EC2 instances come with different pricing options:

  • On-Demand - Pay by the hour without long term commitments. Easy to launch but more expensive per hour.
  • Reserved - Make an upfront payment to receive a significant discount on instance usage over 1-3 years. Great for steady-state workloads.
  • Spot - Bid on spare EC2 capacity and save up to 90%, but instances can be reclaimed with short notice. Useful for batch jobs and fault-tolerant workloads.

Strategies for Cost-Effective AWS Compute Services

To further reduce EC2 costs, leverage tools like:

  • AWS Pricing Calculator - Estimate usage costs across various options. Helps choose most affordable instance types/purchasing options.
  • AWS Trusted Advisor - Provides recommendations to reduce waste for reserved instance coverage, idle load balancers, unused volumes, overprovisioned instances, and more.
  • AWS Cost Explorer - Visualize and track AWS costs over time. Identify top spending categories to target savings opportunities.

Monitoring instance usage and utilization can prevent overprovisioning. Auto Scaling groups dynamically launch/terminate instances based on demand.

Maximizing Savings with AWS Free Tier and Pricing Models

The AWS free tier offers limited usage of certain resources like 750 hours/month of t2.micro or t3.micro instances. This allows experimenting with AWS at no cost.

Combining Reserved Instances for steady-state workloads and On-Demand instances to handle spikes provides a balance of savings and flexibility.

Savings Plans commit to a consistent amount of usage without locking into specific instances. This works well for variable workloads using containers and serverless.

Carefully evaluating instance types, purchasing options, and discounts/free tiers is key to optimizing cloud costs on EC2 long-term.

Scaling and Migrating Workloads with Amazon EC2

Amazon EC2 provides various services and tools to help users scale and migrate workloads efficiently. As applications grow, utilizing these capabilities allows maintaining performance, availability, and cost optimization.

Migration to Amazon EC2: Strategies and Tools

Migrating existing workloads to Amazon EC2 provides increased flexibility, scalability, and cost savings compared to on-premises infrastructure. Some key migration options include:

  • AWS Quick Start Reference Deployments - These automated deployment guides help migrate common workloads like websites, VPNs, databases, and enterprise apps to AWS. They reduce heavy lifting through validated blueprints and infrastructure as code templates.

  • AWS Reference Architecture Center - This resource provides detailed diagrams and step-by-step instructions for migrating complex application architectures to AWS. Guidance is categorized by industry and use case.

  • AWS Application Discovery Service - This service discovers on-premises applications, collects configuration and usage data, and provides migration planning recommendations. The insights help group workloads and design cloud migrations.

  • AWS Database Migration Service (DMS) - DMS allows users to migrate relational and non-relational databases to AWS with minimal downtime. It supports homogeneous and heterogeneous migrations between database platforms.

Choosing the appropriate migration strategy depends on the application architecture, security requirements, and other technical and business considerations. AWS migration partners can also provide specialized assistance.

Auto Scaling EC2 Instances for Demand-Driven Workloads

To maintain application performance during traffic spikes and efficiently scale EC2 capacity, Amazon EC2 Auto Scaling automatically adds or removes instances based on user-defined policies. Key features include:

  • Dynamic Scaling Plans - Define scaling strategies to automatically scale in and out based on changing resource utilization like CPU and memory. This maintains performance and optimizes costs.

  • Predictive Scaling - Proactively scale EC2 capacity based on forecasted load changes using machine learning, minimizing lag in scaling instances.

  • Scheduled Scaling Actions - Scale instance capacity on a schedule to match predictable spikes or dips in application traffic volumes, improving availability.

Auto Scaling works across availability zones to distribute instances, while Elastic Load Balancing routes traffic for high availability.

Implementing Elastic Load Balancing for High Availability

Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple EC2 instances in one or more availability zones. Benefits include:

  • Increased fault tolerance - If an instance fails, ELB reroutes traffic to remaining available instances

  • Improved performance - Workload is distributed efficiently across resources

  • Higher availability - ELB checks instance health, routing traffic only to healthy instances

  • Security - ELB operates at the application layer, obscuring origin servers and providing SSL termination

ELB offers Application, Network, and Gateway load balancing options to suit different architectures. Using Auto Scaling with ELB provides automated scaling of EC2 capacity to maintain performance and availability.

Conclusion: Leveraging AWS EC2 for Scalable Compute

AWS EC2 provides highly flexible and scalable compute capacity to run applications in the AWS Cloud. As software engineers, understanding the core concepts of EC2 is key to leveraging it effectively.

Recap of Flexible Compute Options with Amazon EC2

Amazon EC2 offers a wide selection of instance types optimized for different use cases:

  • General purpose instances like t2.micro provide balanced CPU, memory and network resources for testing, dev and small apps. They offer a cost-effective option.

  • Compute optimized instances feature high CPU performance for compute intensive apps like batch processing, media transcoding and high performance web servers.

  • Memory optimized instances deliver fast performance for workloads that process large datasets in memory like databases and memory caches.

  • Storage optimized instances have high, scalable local storage for data intensive apps like distributed file systems, data warehousing and log processing.

With features like EC2 Auto Scaling, Elastic Load Balancing and instance storage options, EC2 provides the flexible building blocks to scale applications cost-effectively.

Key Storage and Data Management Takeaways

Choosing the right storage option is vital. Amazon EBS volumes allow persistence of data beyond the lifetime of instances. EC2 instance store provides temporary block level storage tied to the lifecycle of the instance.

Understanding application data access patterns is key to selecting between EBS and instance stores. EBS works better for apps needing consistent and durable storage. Instance stores suit temporary data that changes frequently.

Best Practices for Cost and Capacity Management

Tools like Trusted Advisor and the AWS Pricing Calculator help estimate costs. Auto Scaling, Elastic Load Balancing and right-sizing instance types ensure apps have adequate capacity to maintain performance during traffic spikes, while optimizing costs.

Following best practices around storage, data lifecycle management and monitoring resource utilization is key to cost-effectively running apps at scale.

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