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In this tutorial, you’ll learn how to deploy EC2 instances via AWS CloudFormation and monitor their health using the CloudWatch Resource Health dashboard.

Deploying the CloudFormation Stack

Template Overview

The CloudFormation template below launches three t2.micro EC2 instances across different Availability Zones. It automatically retrieves the latest Amazon Linux 2 AMI ID from the AWS Systems Manager (SSM) Parameter Store.

AWSTemplateFormatVersion: '2010-09-09'
Description: Launch 3 EC2 Instances in separate Subnets/AZs

Parameters:
  LatestAmiId:
    Type: AWS::SSM::Parameter::Value<AWS::EC2::Image::Ids>
    Default: /service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2

Resources:
  EC2Instance1:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref LatestAmiId
      InstanceType: t2.micro
      SubnetId: subnet-64e600e

  EC2Instance2:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref LatestAmiId
      InstanceType: t2.micro
      SubnetId: subnet-68cf014

  EC2Instance3:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref LatestAmiId
      InstanceType: t2.micro
      SubnetId: subnet-a5e028e9

Note

Ensure you replace the subnet-xxxxxxx values with valid subnet IDs from your VPC before deployment.

Open the AWS Management Console and navigate to CloudFormation.
Choose Create stack > With new resources (standard).
Under Template source, select Upload a template file and upload resource_health.yaml.
Click Next, name your stack (e.g., resource-health-demo), then proceed through the configuration pages.
Review and click Create stack to launch the resources.

The image shows the AWS CloudFormation console where a user is in the process of creating a stack. The interface allows the user to prepare and specify a template, with options to upload a template file or use other sources.

Verifying Stack Creation

Return to the CloudFormation dashboard and monitor the stack status. Deployment completes when the status changes to CREATE_COMPLETE.

Warning

Stack creation can take several minutes. Do not interrupt the process or delete the stack until it reaches CREATE_COMPLETE.

The image shows an AWS CloudFormation console with details of two stacks: "resource-health-demo" and "xray-sample." The "resource-health-demo" stack is in a "CREATE_COMPLETE" status, while "xray-sample" has a "DELETE_FAILED" status.

Confirming EC2 Instances

Once the stack reaches CREATE_COMPLETE, go to the EC2 console. Under Instances, verify that three t2.micro instances are Initializing or Running.

The image shows an AWS EC2 dashboard with three running instances, each with the instance type "t2.micro" and status "Initializing."

Exploring the CloudWatch Resource Health Dashboard

The CloudWatch Resource Health dashboard gives you a centralized view of instance-level metrics and status checks:

Open the CloudWatch console and select Resource Health.
Choose EC2 as the resource type.

Initially, CPU charts may take up to five minutes to populate. Once data is available, customize your view:

Dimension	Options	Use Case
Metric	CPUUtilization, StatusCheckFailed	Monitor CPU load and health checks
Group by	Availability Zone, Instance Type, Image ID	Visualize grouping by AZ or instance
Sort by	CPUUtilization, StatusCheckFailed, Instance ID	Quickly identify high-usage instances

In Map view, instances are color-coded by CPU utilization:

Blue: < 25%
Green: 25%–50%
Yellow: 50%–75%
Red: > 75%

Switch to List view for a detailed table showing:

CPU and memory usage (Memory requires [CloudWatch Agent] installation)
Alarm state
System and instance status checks

The image shows an AWS CloudWatch Resource Health dashboard for EC2, displaying a status check with all checks passed.

Note

For large environments (hundreds of instances), use filters and grouping by tags, subnets, or Auto Scaling groups to quickly narrow down potential issues.

Conclusion

You’ve learned how to:

Deploy EC2 instances with AWS CloudFormation
Retrieve the latest AMI via SSM Parameter Store
Monitor instance health and metrics using the CloudWatch Resource Health dashboard

This workflow scales seamlessly across large fleets, ensuring proactive maintenance and rapid troubleshooting.

References

AWS CloudFormation Documentation: https://docs.aws.amazon.com/cloudformation/
Amazon EC2 User Guide: https://docs.aws.amazon.com/ec2/
Amazon CloudWatch User Guide: https://docs.aws.amazon.com/cloudwatch/
AWS Systems Manager Parameter Store: https://docs.aws.amazon.com/systems-manager/maintenance-windows/latest/userguide/parameter-store.html

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