EKS vs. ECS vs. AWS Fargate: Understanding the Technical and Operational Differences

Overview

Which AWS container platform is the right one for your application? That’s a nuanced question, but one that deserves some exploration. Amazon offers three key platforms for containerized workloads: Amazon Elastic Kubernetes Service (EKS), Amazon Elastic Container Service (ECS), and AWS Fargate.

Each of these services is designed to manage containerized applications, but they serve different use cases. For CloudOps and ContainerOps teams, understanding the nuances between EKS, ECS, and Fargate is critical for selecting the right solution. It also goes beyond just the technical aspects. There are also operational overheads and business implications, including costs, to consider.

Let’s explore the technical differentiation, operational overhead, and cost implications of each service to help you understand the impact of the choices.

Amazon EKS: Full Power of Kubernetes with Operational Overhead

Amazon Elastic Kubernetes Service (EKS) is a fully managed Kubernetes service that simplifies running Kubernetes on AWS without the operational complexity of managing the control plane. Kubernetes (K8s) is known for its flexibility and powerful ecosystem, making it a go-to for organizations that need advanced container orchestration.

Technical Differentiation for EKS

EKS leverages the full power of Kubernetes, meaning you’re not limited by the features AWS provides. You’re free to use the extensive K8s ecosystem for managing applications, such as Helm charts, custom controllers, and CRDs (Custom Resource Definitions). However, this comes with trade-offs.

Kubernetes is a complex beast. While EKS handles the control plane, your team is responsible for managing the worker nodes. This means dealing with scaling, patching, and configuring your nodes. EKS lets you connect to any K8s-compatible tooling, but the flip side is that you’re also on the hook for its operational quirks.

Operational Overhead with EKS

With EKS, the control plane is AWS’s responsibility, but node management is yours. This means maintaining the AMIs (Amazon Machine Images) for worker nodes, scaling your cluster, implementing security updates, and monitoring. You’re also dealing with the complexity of managing networking components like service mesh and ingress controllers.

This adds operational overhead and requires teams with a deep understanding of Kubernetes. You’re also paying for both the EKS control plane (currently $0.10 per hour) and the underlying EC2 instances.

Example: A Simple Kubernetes Node Group YAML for EKS

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
  name: eks-cluster
  region: us-west-2
nodeGroups:
  - name: worker-group
    instanceType: t3.medium
    desiredCapacity: 3
    volumeSize: 20
    ssh:
      allow: true

Cost Implications with EKS

EKS introduces additional costs on top of EC2 instance pricing. You pay per cluster, so running multiple clusters can increase costs. Additionally, you’ll need to factor in the engineering effort to manage and monitor the infrastructure.

However, if your use case demands Kubernetes’ vast ecosystem, EKS can be worth the investment. Kubernetes’s ability to handle complex microservice architectures or multi-cloud environments can outweigh the higher operational costs.

Amazon ECS: Simplicity at Scale, but with Limitations

Amazon Elastic Container Service (ECS) is Amazon’s native container management service. It simplifies deployment and scaling of containerized applications, especially in environments heavily tied to AWS services. ECS natively integrates with other AWS offerings like IAM, CloudWatch, and ELB, which makes it attractive for teams invested in the AWS ecosystem.

Technical Differentiation for ECS

ECS abstracts away much of the complexity of container orchestration. Unlike Kubernetes, ECS is AWS-native, meaning you don’t have the overhead of managing complex control planes or third-party integrations. ECS uses task definitions, services, and clusters to manage containers.

However, this simplicity comes with limitations. ECS doesn’t offer the same level of flexibility as Kubernetes. For instance, you won’t find the extensive library of third-party tools that K8s offers. This makes ECS less ideal for teams that require complex orchestration scenarios or custom integrations.

Operational Overhead with ECS

ECS reduces operational overhead significantly. AWS manages the underlying infrastructure for the control plane, and depending on your setup, worker node management can be simplified. ECS also scales more easily because it’s tightly integrated with AWS services.

However, if you manage ECS on EC2 instances, you’ll still have to maintain the underlying instances yourself. Tasks like patching, scaling, and monitoring fall on your shoulders, much like with EKS, but with a slightly simpler operational model.

Example: ECS Task Definition JSON

{
  "family": "ecs-task",
  "containerDefinitions": [
    {
      "name": "my-app",
      "image": "nginx",
      "memory": 512,
      "cpu": 256,
      "essential": true
    }
  ]
}

Cost Implications with ECS

ECS can be more cost-effective than EKS because you avoid the additional Kubernetes overhead. Since ECS is more deeply integrated with AWS, you get out-of-the-box solutions for logging, monitoring, and scaling, reducing the need for extra engineering effort. However, if you require multi-cloud support or advanced networking setups, ECS may not be the best fit.

Running ECS on EC2 instances still incurs EC2 costs, but you save on operational complexity and management overhead compared to EKS.

AWS Fargate: Serverless Simplicity, But at a Premium

AWS Fargate is a serverless compute engine for containers that works with both ECS and EKS. It abstracts away the need to manage underlying infrastructure, allowing you to run containers without worrying about servers or clusters. Fargate is the easiest option in terms of operational overhead, but it can be expensive at scale.

Technical Differentiation for AWS Fargate

Fargate abstracts away virtually all infrastructure management. There are no instances to manage, patch, or scale. You define your tasks, and Fargate takes care of the rest. This makes Fargate ideal for small teams or applications that require minimal operational complexity.

However, Fargate’s simplicity comes at the cost of flexibility. Since you don’t control the underlying instances, you lose some of the configurability you would have with EC2 or Kubernetes worker nodes. For example, you have less control over networking settings or the ability to use custom AMIs.

Operational Overhead with AWS Fargate

Fargate reduces operational overhead to near zero. Since AWS handles all the infrastructure, your only focus is on your containerized applications. There’s no need to worry about scaling clusters, patching instances, or setting up complex networking. This makes it a great option for teams that want to focus purely on application development and deployment.

However, Fargate has limitations when it comes to advanced use cases. For instance, if you require specific networking setups or high-performance workloads that need GPU support, Fargate may not meet your needs.

Example: ECS Task Definition for Fargate

{
  "family": "fargate-task",
  "networkMode": "awsvpc",
  "containerDefinitions": [
    {
      "name": "my-fargate-app",
      "image": "nginx",
      "memory": 512,
      "cpu": 256,
      "essential": true
    }
  ],
  "requiresCompatibilities": ["FARGATE"],
  "cpu": "256",
  "memory": "512"
}

Cost Implications with AWS Fargate

Fargate can be more expensive than ECS or EKS, especially at scale. While you save on operational costs, the compute pricing is higher. For example, you pay based on vCPU and memory used by your containers, which can quickly add up in high-traffic applications.

That said, for small applications or development environments, the reduction in operational overhead may justify the higher per-unit cost.

Application Patterns and Their Impact on EKS, ECS, and Fargate Decisions

When choosing between EKS, ECS, and Fargate, it’s essential to remember that your mileage may vary depending on the application you’re running. Different application patterns have varying infrastructure needs, and the right platform often hinges on these specific requirements. Let’s explore how these services stack up for three common application patterns: a small pod, a horizontally scalable app, and a multi-cloud app.

1. Small Pod Application: Minimal Infrastructure, Limited Traffic

For a small, self-contained application running a handful of containers, such as a microservice or a small pod-based app that doesn’t see high traffic, AWS Fargate is an interesting choice.

• Why Fargate?
  • Fargate’s serverless model eliminates the need to manage infrastructure, making it perfect for small-scale apps. You simply define your container specs, and AWS takes care of the rest.
  • With Fargate, you pay for exactly the CPU and memory your containers use. This is advantageous for small, low-traffic apps, where infrastructure costs can be minimized.
  • The reduced operational overhead frees up time and resources, allowing small teams to focus on feature development rather than infrastructure management.
• Why not EKS or ECS?
  • While you could run a small app on ECS or EKS, the operational complexity and overhead of managing nodes (in ECS/EC2 or EKS) is likely overkill for such a small workload. You would be managing infrastructure for an app that doesn’t necessarily need that level of control.

Example Use Case: A small internal microservice, such as a Slack bot or a tiny API for internal tools, where traffic is predictable and scalability isn’t a major concern.

2. Horizontally Scalable Application: High Traffic, Autoscaling Required

For a horizontally scalable application that needs to handle spikes in traffic (e.g., an e-commerce website or a high-demand API), ECS on EC2 or EKS are solid options, depending on the level of flexibility and control you need.

• Why ECS on EC2?
  • ECS on EC2 provides a more straightforward solution that allows for tight integration with AWS services like Auto Scaling and Elastic Load Balancing (ELB). If your app scales horizontally and you want to keep infrastructure simple while using EC2 instances, ECS works well.
  • ECS’s native integration with Auto Scaling means your application can automatically scale up and down based on demand, reducing the complexity of managing Kubernetes.
• Why EKS?
  • If your app requires advanced Kubernetes features—such as custom autoscaling policies, custom networking setups, or you plan to manage multi-service deployments—EKS might be the better fit.
  • EKS allows you to leverage Kubernetes-native scaling solutions like the Horizontal Pod Autoscaler (HPA) or Vertical Pod Autoscaler (VPA), which can optimize resource usage dynamically based on real-time metrics.
• Why not Fargate?
  • While Fargate can handle autoscaling, it becomes expensive for horizontally scalable applications with high traffic. The per-unit cost of Fargate vCPU and memory can escalate rapidly as the application scales, making EC2-backed ECS or EKS clusters more cost-efficient in the long run.

Example Use Case: An e-commerce site or a SaaS application that experiences daily traffic fluctuations, requiring robust autoscaling and integration with services like ELB.

3. Multi-Cloud Application: Cloud-Agnostic, Complex Deployments

For an application that needs to run across multiple cloud providers—whether for disaster recovery, compliance, or global reach—EKS is the clear winner.

• Why EKS?
  • Kubernetes, the backbone of EKS, was designed for portability. EKS makes it easier to implement a multi-cloud strategy, enabling you to run Kubernetes clusters across different cloud providers (e.g., AWS, GCP, Azure). You can use tools like Cluster API to manage multiple Kubernetes clusters, including those outside of AWS.
  • EKS supports complex network configurations and multi-region deployments, which are common in multi-cloud strategies. You can configure your cluster to span AWS regions or integrate with other cloud providers while maintaining the same Kubernetes control plane.
  • EKS’s ecosystem allows you to build more advanced multi-cloud strategies using service meshes like Istio or Linkerd to manage traffic and services across clouds seamlessly.
• Why Not ECS or Fargate?
  • ECS is deeply tied to the AWS ecosystem and does not support multi-cloud deployments natively. If your application requires cloud-agnostic deployments, ECS limits your flexibility.
  • Fargate is also AWS-bound, and its serverless nature doesn’t lend itself to complex, cloud-agnostic deployments. If multi-cloud portability is essential, Fargate’s serverless model falls short.

Example Use Case: A global SaaS application serving customers across different continents with a requirement to run workloads in multiple regions and clouds for redundancy, failover, or compliance reasons.

The overall guidance for which platform to choose for your application will depend on today’s technical requirements and your spending tolerance and is based on today’s consumption data. Another thing to remember is that your application usage will change over time, so selecting a scalable option for your application is important. 

Business and Technical Reasons to Choose Each

There are a few key questions that help to narrow down which container hosting platform on AWS is the optimal choice for you. These are a combination of the technical requirements and the business requirements for how you deploy and manage applications.

When to Choose EKS:

• You need Kubernetes’ advanced features like Helm, custom controllers, or CRDs.
• Your team has the Kubernetes expertise required to manage the added complexity.
• You plan to run multi-cloud or hybrid architectures.
• You’re managing complex microservice architectures, where Kubernetes shines.

When to Choose ECS:

• You’re deeply invested in the AWS ecosystem and prefer AWS-native solutions.
• You want simpler container orchestration without the complexity of Kubernetes.
• Your applications primarily run on AWS and don’t require multi-cloud compatibility.
• You want tight integration with AWS services out of the box.

When to Choose Fargate:

• You want to minimize infrastructure management as much as possible.
• Your application scales dynamically, and you don’t want to manage clusters.
• Your workloads are straightforward and don’t require custom instance configurations.
• Cost is less of a concern than reducing operational overhead.

Which is the best for your applications:  EKS, ECS, or Fargate?

Choosing between EKS, ECS, and Fargate depends on your technical requirements and your business priorities. EKS offers powerful flexibility at the cost of higher operational overhead, while ECS provides a more streamlined experience tightly integrated with AWS. Fargate, meanwhile, offers the least operational burden but comes with a higher price tag.

If your workloads demand full control and advanced Kubernetes features, EKS may be the right fit. If simplicity and AWS integration are your priorities, ECS makes sense. For those who want to offload as much infrastructure management as possible, Fargate is a strong contender, but be prepared to pay a premium for the convenience.

Ultimately, understanding these trade-offs will help you better assess the costs associated with each platform, allowing you to make a smarter decision for both your team and your bottom line.

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