Creating an ECS Cluster - ECS Tutorial


An ECS cluster is a logical grouping of container instances where you can run and manage your containerized applications. In this tutorial, you will learn how to create an ECS cluster in Amazon Elastic Container Service (ECS) and configure the necessary resources to support your containers.

Step 1: Set Up a Virtual Private Cloud (VPC)

A VPC is required to create an ECS cluster. Follow these steps to create a VPC:

  1. Sign in to the AWS Management Console and navigate to the VPC service.
  2. Create a new VPC and configure its IP address range.
  3. Create subnets within the VPC across different availability zones.
  4. Configure route tables and internet gateways to enable internet access for your cluster.

Step 2: Configure Security Groups

Security groups control inbound and outbound traffic to your container instances. Follow these steps to configure security groups:

  1. Create a security group and define inbound rules to allow traffic from specific ports or IP ranges.
  2. Associate the security group with the subnets in your VPC.

Step 3: Launch Container Instances

The next step is to launch container instances within your ECS cluster. This can be done using Amazon EC2 instances or AWS Fargate. Here's an example using EC2 instances:

aws ecs create-cluster --cluster-name my-ecs-cluster

This command creates an ECS cluster with the specified name.

Common Mistakes

  • Not properly configuring VPC settings, leading to network connectivity issues for container instances.
  • Missing or incorrect security group rules, resulting in network traffic being blocked to the cluster.
  • Launching container instances without the required permissions, causing authentication or authorization errors.

Frequently Asked Questions (FAQs)

Q1: Can I create multiple clusters in ECS?

A1: Yes, you can create multiple ECS clusters to separate different environments or applications.

Q2: How do I choose between EC2 instances and AWS Fargate for launching container instances?

A2: The choice depends on your specific requirements. EC2 instances provide more control and flexibility, while AWS Fargate offers serverless container execution.

Q3: Can I resize an ECS cluster?

A3: Yes, you can scale the size of an ECS cluster by adding or removing container instances.

Q4: What is the difference between a VPC and a subnet?

A4: A VPC is a virtual network in AWS that you create, while subnets are subdivisions of the VPC's IP address range and are associated with specific availability zones.

Q5: How do I associate a task with an ECS cluster?

A5: You can associate a task with an ECS cluster by specifying the cluster name in the task definition.


In this tutorial, you learned how to create an ECS cluster in Amazon Elastic Container Service (ECS). By setting up a VPC, configuring security groups, and launching container instances, you can create a scalable and reliable environment for running your containerized applications. Avoid common mistakes such as misconfiguring VPC settings or security groups, and ensure that your container instances have the necessary permissions. With your ECS cluster set up, you are ready to deploy and manage your containers with ease.