> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Demo Resource Health

> This tutorial teaches deploying EC2 instances with AWS CloudFormation and monitoring their health using the CloudWatch Resource Health dashboard.

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.

```yaml theme={null}
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
```

<Callout icon="lightbulb" color="#1CB2FE">
  Ensure you replace the `subnet-xxxxxxx` values with valid subnet IDs from your VPC before deployment.
</Callout>

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

<Frame>
  ![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.](https://kodekloud.com/kk-media/image/upload/v1752862336/notes-assets/images/AWS-CloudWatch-Demo-Resource-Health/aws-cloudformation-console-create-stack.jpg)
</Frame>

***

## Verifying Stack Creation

Return to the **CloudFormation** dashboard and monitor the stack status. Deployment completes when the status changes to **CREATE\_COMPLETE**.

<Callout icon="triangle-alert" color="#FF6B6B">
  Stack creation can take several minutes. Do not interrupt the process or delete the stack until it reaches `CREATE_COMPLETE`.
</Callout>

<Frame>
  ![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.](https://kodekloud.com/kk-media/image/upload/v1752862338/notes-assets/images/AWS-CloudWatch-Demo-Resource-Health/aws-cloudformation-stacks-status-diagram.jpg)
</Frame>

***

## 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**.

<Frame>
  ![The image shows an AWS EC2 dashboard with three running instances, each with the instance type "t2.micro" and status "Initializing."](https://kodekloud.com/kk-media/image/upload/v1752862339/notes-assets/images/AWS-CloudWatch-Demo-Resource-Health/aws-ec2-dashboard-three-instances-initializing.jpg)
</Frame>

***

## Exploring the CloudWatch Resource Health Dashboard

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

1. Open the **CloudWatch** console and select **Resource Health**.
2. 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

<Frame>
  ![The image shows an AWS CloudWatch Resource Health dashboard for EC2, displaying a status check with all checks passed.](https://kodekloud.com/kk-media/image/upload/v1752862340/notes-assets/images/AWS-CloudWatch-Demo-Resource-Health/aws-cloudwatch-ec2-health-dashboard.jpg)
</Frame>

<Callout icon="lightbulb" color="#1CB2FE">
  For large environments (hundreds of instances), use filters and grouping by tags, subnets, or Auto Scaling groups to quickly narrow down potential issues.
</Callout>

***

## 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/](https://docs.aws.amazon.com/cloudformation/)
* Amazon EC2 User Guide: [https://docs.aws.amazon.com/ec2/](https://docs.aws.amazon.com/ec2/)
* Amazon CloudWatch User Guide: [https://docs.aws.amazon.com/cloudwatch/](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](https://docs.aws.amazon.com/systems-manager/maintenance-windows/latest/userguide/parameter-store.html)

<CardGroup>
  <Card title="Watch Video" icon="video" cta="Learn more" href="https://learn.kodekloud.com/user/courses/aws-cloudwatch/module/74326609-21c0-467c-a033-b526c2af16f2/lesson/2d93b7da-3bbc-4c7a-9c60-cd57883a8177" />

  <Card title="Practice Lab" icon="installation" cta="Learn more" href="https://learn.kodekloud.com/user/courses/aws-cloudwatch/module/74326609-21c0-467c-a033-b526c2af16f2/lesson/b94d816a-69ff-41e2-9050-98ed33e7e193" />
</CardGroup>