Amazon ECS vs Amazon EC2: What’s Best for Modern Cloud?

In the dynamic landscape of cloud computing, the choices you make today can set the trajectory for your organization’s future. As AWS continues to evolve, two of its services, EC2 and ECS, often find themselves at the center of debates and strategic decisions.

But which one aligns with the demands of modern cloud architecture? In this article, we’ll dive deep into the capabilities of both ECS and EC2, shedding light on their strengths, nuances, and best-fit scenarios.

Whether you’re an enterprise architect, a budding developer, or a business leader, understanding this pivotal difference can be a game-changer.

Join us as we demystify the future of AWS compute and help you make an informed choice for your next cloud project.

Amazon EC2: An Overview

Amazon Elastic Compute Cloud (EC2) is one of the first services was available in AWS Cloud that allowed you to run and manage your own virtual servers. You have the freedom to install and manage the Operating System (OS).

Key Features of EC2

  • Virtual Servers in the Cloud: Spin up instances (that’s what AWS calls these virtual servers) based on your needs.
  • Customizable Instance Types: From memory-optimized to GPU-intensive tasks, there’s an instance type for that.
  • Scalability and Elasticity: Whether you’re expecting a handful of users or a sudden surge, EC2 can handle it.
  • Integration with AWS Services: EC2 plays well with other AWS services, making it a versatile choice.

Typical EC2 Use Cases

  • Hosting Web Applications: From simple blogs to complex web apps, EC2 can host it.
  • Data Processing: Crunching numbers? EC2 instances can be your number-crunching workhorses.
  • High-Performance Computing: For those tasks that need a little extra oomph.

Amazon ECS: An Overview

Amazon Elastic Container Service (ECS) is a container orchestration service which let’s you host and run docker containers. 

Key Features of ECS

  • Container Orchestration Service: Manage and scale your Docker containers with ease.
  • Supports Docker Containers: It’s in the name! ECS is built for Docker.
  • Integration with AWS Fargate: Go serverless! No need to worry about the underlying infrastructure.
  • Service Discovery and Load Balancing: Ensure your services are highly available and fault-tolerant.

Typical ECS Use Cases

  • Microservices Architectures: Break down your apps into smaller, manageable pieces.
  • Batch Processing: Got a lot of tasks? Process them in containers.
  • CI/CD: Continuous integration and deployment are a breeze with ECS.

Key differences between Amazon ECS and Amazon EC2

One of the key differences between ECS and EC2 is the way you develop and deploy your applications in the Cloud. Amazon EC2 is a service designed to provide resizable compute capacity in the cloud, allowing users to run virtual machines and have control over their computing environment, making it suitable for a wide range of applications, including those requiring specific configurations and a full OS.

In contrast, Amazon ECS is a highly scalable, high-performance container orchestration service that supports Docker containers and allows you to easily run and scale containerised applications on AWS, abstracting away the infrastructure layer and focusing more on managing application deployment, which is ideal for microservices architectures and modern application development practices.

Comparison table

Before we dive deeper, you’ll find a comparison table that gives you a quick overview of the major differences between ECS and EC2:

CapabilityAmazon EC2Amazon ECS
Compute ParadigmProvides Virtual Machines (VMs) to run applications.A container management service that supports Docker containers.
Management OverheadRequires manual management of server instances.Focuses on application management, abstracting infrastructure.
ScalabilityUses Auto Scaling Groups for scaling.Offers service-based scaling for containers.
Pricing ModelPay for reserved or on-demand instances.Pay for vCPU and memory that your containerised applications use.
Deployment SpeedTakes longer due to VM boot-up times.Faster, as containers can be launched in seconds.
Resource EfficiencyLess efficient due to OS overhead for each instance.More efficient as containers share the OS kernel.
PortabilityDependent on AMIs, which are region-specific.Containers are inherently portable across different environments.
Development StyleSuited for monolithic or traditional applications.Ideal for microservices-based application architectures.
Use CasesGeneral-purpose computing, suitable for a wide range of apps.Suited for applications that benefit from containerization.
Image TypeUses Amazon Machine Images (AMIs).Uses Docker images.
Comparison table between EC2 and ECS

Alright, now that we’ve gone through the quick comparison. Let’s get into the meat and potatoes: what sets ECS and EC2 apart? We’re talking about compute, management, scalability, and machine images. Let’s break it down.

Compute Paradigm

EC2: At its core, EC2 is about providing virtualized computing resources over the internet. When you use EC2, you’re essentially renting virtual machines (VMs) where you can run your applications. These VMs can be customized in terms of CPU, memory, storage, and networking capabilities.

ECS: ECS, on the other hand, is a container management service. Instead of dealing with VMs, you’re working with Docker containers. Containers are lightweight, standalone, and executable software packages that encompass all the necessary code, runtime, system tools, and libraries to run an application. With ECS, you’re focusing on deploying, managing, and scaling these containers.

Management Overhead

EC2: With EC2, there’s a higher degree of management overhead. You’re responsible for patching the OS, ensuring security compliance, and managing the instance lifecycle. While AWS provides tools to automate some of these tasks, there’s still a level of hands-on management required.

ECS: ECS abstracts away much of the infrastructure management. You don’t need to worry about the OS or the underlying infrastructure. Instead, you focus on defining tasks and services, and ECS takes care of deploying and maintaining them. Especially when combined with AWS Fargate, the serverless compute engine for containers, the management overhead is significantly reduced.


EC2: Scaling in EC2 can be manual or automated using Auto Scaling Groups (ASG). With ASG, you can define scaling policies based on specific metrics (like CPU utilization), ensuring your application has the right amount of resources. However, scaling requires spinning up new VM instances, which can take time.

ECS: ECS offers service-based scaling. You can define how many instances of a containerized application you want running, and ECS will ensure that number is maintained. If a container fails, ECS will replace it. Scaling containers can be faster than VMs since containers are more lightweight and share the same OS kernel.

Machine Image

One of the foundational differences between EC2 and ECS lies in the way applications and environments are packaged and distributed. Let’s delve into the distinction between Amazon Machine Images (AMIs) and Docker images.

EC2 – AMI (Amazon Machine Image):

  • Definition: An AMI is a pre-configured virtual machine image used to create EC2 instances. It packages up the operating system and any additional software required.
  • Customization: While you can create custom AMIs, it’s a relatively heavyweight process. Any change, even a minor one, requires a new AMI to be created and stored.
  • Portability: AMIs are region-specific in AWS. If you want to launch an instance in a different region, you’d need to copy the AMI to that region.
  • Size: AMIs are generally larger in size as they include the entire OS and all software components. This can lead to longer boot times for EC2 instances.
  • Versioning: AWS doesn’t provide native versioning for AMIs. You’d need to manage versions manually or through naming conventions.

ECS – Docker Image:

  • Definition: A Docker image is a lightweight, standalone package that contains everything needed to run a piece of software, including the code, runtime, system tools, and libraries.
  • Customization: Docker images are built from Dockerfiles, which are essentially scripts that define how the image should be constructed. Making changes is as simple as updating the Dockerfile and rebuilding the image.
  • Portability: Docker images are inherently portable. You can run the same Docker image on your local machine, in any cloud environment, or even on different OS platforms, provided Docker is installed.
  • Size: Docker images are typically much smaller than AMIs since they only contain the application and its direct dependencies. This leads to faster start times for containers.
  • Versioning: Docker has built-in versioning for images. Each time you push an image to a registry (like Docker Hub or Amazon ECR), you can tag it with a version number.

In essence, while AMIs provide a full virtual machine environment, Docker images focus on packaging just the application and its immediate environment. This makes Docker images more agile, portable, and efficient, aligning well with modern development and deployment practices.

For organizations looking to achieve faster deployment times, better resource utilization, and greater flexibility, the Docker image approach of ECS offers clear advantages over the traditional AMI method of EC2.

When to Use Amazon ECS and EC2

In the vast AWS ecosystem, both ECS and EC2 have carved out significant niches. However, as cloud computing evolves, the advantages of ECS, especially in the context of modern application development, are becoming more pronounced.

Let’s explore scenarios where each shines and delve deeper into why ECS might be the better choice for many organizations.

Choose EC2 when..

EC2 is the go-to solution for a variety of scenarios:

  • Full Control: If you need granular control over the OS, software patches, and the environment, EC2 offers that flexibility.
  • Legacy Applications: For applications that aren’t containerized and might require specific VM configurations or dependencies, EC2 is a natural fit.
  • Specific Infrastructure Requirements: If you have particular networking, storage, or compute needs that aren’t yet aligned with container orchestration, EC2 provides a broader range of customization.

Choose ECS when…

ECS is rapidly becoming the preferred choice for several reasons:

  • Microservices Architecture: ECS is tailor-made for microservices. By breaking applications into smaller, independent services, you can achieve better scalability, manageability, and agility.
  • Consistency: With ECS, you’re deploying containers, ensuring that your application runs the same, whether in development, staging, or production. This uniformity reduces deployment issues and streamlines the development process.
  • Resource Efficiency: Containers typically have a smaller footprint than VMs. This efficiency means you can often run more applications on the same hardware, leading to cost savings.
  • Rapid Deployment and Scalability: Containers can be spun up in seconds, allowing applications to scale quickly in response to demand. This speed is especially crucial for applications with variable traffic patterns.
  • Simplified Management: With ECS, especially when paired with Fargate, much of the infrastructure management is abstracted away. This abstraction allows developers to focus on code and applications, not on managing servers.

Why using Amazon ECS Might Just Be Your Best Bet

Navigating the vast landscape of AWS services can be a challenge, especially when two services seem to overlap in functionality. But if you’re looking to modernize your applications, reduce overhead, and embrace the future of application deployment, ECS stands out as a compelling choice over EC2.

Here’s why:

  1. Simplified Management: With ECS, much of the infrastructure management is abstracted away. No more worrying about patching the OS or dealing with the intricacies of instance management. This means you can focus more on your application and less on the underlying infrastructure.
  2. Fast Scaling: Containers are lightweight and can be spun up rapidly. If your application experiences a sudden surge in traffic, ECS can scale out quickly, ensuring a smooth user experience. In contrast, spinning up new VMs in EC2 can take longer, potentially leading to performance bottlenecks.
  3. Cost Efficiency: With ECS, especially when paired with Fargate, you pay for the exact vCPU and memory your tasks consume. This granular pricing model can lead to cost savings, especially for variable workloads that don’t need a VM running 24/7.
  4. Modern Application Development: The world is moving towards microservices and containerized applications. ECS is purpose-built for this paradigm, making it easier to develop, deploy, and manage modern applications. If you’re looking to future-proof your application architecture, ECS is a step in the right direction.
  5. Integrated Ecosystem: While EC2 has broad integrations, ECS offers a more focused, container-centric ecosystem. From the Elastic Container Registry (ECR) for storing container images to seamless integration with Application Load Balancers, ECS provides a cohesive environment for container management.

In the ever-evolving world of cloud computing, staying ahead of the curve is crucial. While EC2 has its merits and is an excellent choice for many scenarios, if you’re looking to embrace the future of application deployment and management, ECS is a compelling option. Dive in, experiment, and you might just find that ECS aligns perfectly with your cloud aspirations.

Transitioning from EC2 to ECS

Making the move from EC2 to ECS can seem daunting, especially if you’ve heavily invested in EC2-based architectures.

However, the benefits of containerization and the efficiencies offered by ECS can make this transition worthwhile.

Let’s delve deeper into the process, benefits, and considerations of this shift.

Steps to Containerise an Application

  1. Assessment: Begin by evaluating your current EC2-based applications. Identify which applications are suitable for containerization and which might require significant refactoring.
  2. Containerization: Convert applications into containerized versions using Docker. This step involves creating Dockerfiles, optimizing dependencies, and ensuring that applications can run in isolated environments.
  3. ECS Cluster Setup: Set up an ECS cluster. Decide if you’ll be using the EC2 launch type (where you manage the instances) or the Fargate launch type (serverless).
  4. Service and Task Definitions: Define ECS tasks (the containers and their settings) and services (how tasks are scaled and maintained).
  5. Data Management: If your applications rely on databases or storage, consider how you’ll manage data. Options include using Amazon RDS, Amazon EFS, or other AWS data services.
  6. Networking and Security: Set up VPCs, security groups, and IAM roles to ensure that your ECS tasks can communicate securely and effectively.
  7. Testing: Before fully transitioning, test your containerized applications in a staging environment. Ensure that they perform as expected under various conditions.
  8. Deployment and Monitoring: Once satisfied, deploy your applications on ECS. Utilize AWS monitoring tools like CloudWatch to keep an eye on performance and resource utilization.

Benefits of Transitioning

  • Operational Efficiency: With ECS, you can often achieve higher resource utilization, leading to cost savings.
  • Deployment Speed: Containers can be launched in seconds, allowing for faster application scaling and deployment.
  • Flexibility: With ECS, especially when combined with Fargate, you can focus on your application code and not the underlying infrastructure.
  • Innovation: Embracing ECS can position your organization at the forefront of cloud-native development, opening doors to other AWS services and modern development practices.

Challenges and Considerations

  • Learning Curve: If your team is new to Docker and container orchestration, there might be a learning curve. Consider training or workshops.
  • Refactoring: Not all applications are immediately suitable for containerization. Some might require significant changes.
  • Cost Implications: While ECS can be more cost-effective in the long run, the initial transition might have associated costs, especially if refactoring is needed.
  • Integration with Existing Tools: Ensure that your current CI/CD tools, monitoring solutions, and other software can integrate seamlessly with ECS.


In conclusion, while EC2 remains a robust and versatile choice, the advantages of ECS in terms of efficiency, modernization, and developer productivity are hard to ignore. For organizations looking to stay ahead in the cloud game, ECS offers a compelling path forward.

I’ve provided links to the official Amazon Web Services docs if you prefer to dive deeper in Amazon ECS and EC2: 

Danny Steenman

A Senior AWS Cloud Engineer with over 9 years of experience migrating workloads from on-premises to AWS Cloud.

I have helped companies of all sizes shape their cloud adoption strategies, optimizing operational efficiency, reducing costs, and improving organizational agility.

Connect with me todayΒ to discuss your cloud aspirations, and let’s work together to transform your business by leveraging the power of AWS Cloud.

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