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Amazon ECS vs EKS vs Lambda — Compute Service Decision Guide
Learn when to choose Amazon ECS, EKS, or Lambda for your compute needs. Understand exam traps and key architectural decisions.
When choosing a compute service in AWS, the decision can significantly impact your architecture. Understanding when to use Amazon ECS, EKS, or Lambda is crucial for both practical implementations and passing the AWS Certified Solutions Architect - Associate (SAA-C03) exam.
When to Choose Amazon ECS, EKS, or Lambda
Amazon ECS
Use Amazon ECS when you want a straightforward way to run Docker containers within AWS. This service is fully managed and integrates well with other AWS offerings. It’s best for teams that prefer simplicity and want to avoid the overhead of managing Kubernetes.
Amazon EKS
Opt for Amazon EKS when your applications require Kubernetes features, such as custom configurations or portability across different environments. EKS is essential for teams familiar with Kubernetes who want to leverage its ecosystem.
AWS Lambda
AWS Lambda is ideal for running code in response to events without managing servers. This serverless option is perfect for microservices architectures or applications that need to scale automatically based on demand.
| Feature | Amazon ECS | Amazon EKS | AWS Lambda |
|---|---|---|---|
| Management | Fully managed | Managed Kubernetes | Serverless |
| Use Case | Docker container orchestration | Kubernetes applications | Event-driven code execution |
| Launch Types | EC2, Fargate | Managed, self-managed | N/A |
| Execution Time Limit | N/A | N/A | 15 minutes max |
| Cold Start Issues | Minimal | Moderate | Significant if in VPC |
How the Exam Tests This
Understanding how AWS tests your knowledge on these services can help you prepare effectively. Here are some specific patterns:
- Scenario-based questions: Expect scenarios where you must choose the right service based on application requirements. For example, a question may describe a need for rapid scaling and ask whether ECS, EKS, or Lambda is more suitable.
- Comparative questions: The exam may ask you to compare features, such as the differences between Fargate and EC2 launch types in ECS or the benefits of managed node groups in EKS.
- Gotchas related to IAM and networking: Watch out for questions that test your understanding of IAM roles with EKS or VPC configurations that can impact Lambda’s performance.
The Rule to Remember
Choose Amazon ECS for simple Docker deployments, EKS for Kubernetes needs, and Lambda for serverless, event-driven applications.
For further practice, Take the free SAA-C03 mock exam.