Create FIS Experiment

AWS Fault Injection Simulator (FIS) helps you test the resilience of your applications by safely inducing faults. In this guide, we’ll define and launch an FIS experiment using three core components: Actions, Targets, and Stop Conditions. You’ll also learn how to apply guardrails to contain the blast radius.

Core Components
Prerequisites
Step 1: Define the Action
Step 2: Specify the Target
Step 3: Add a Stop Condition
Step 4: Launch the Experiment
Cleanup
Links and References

Core Components

Component	Description	Example
Action	The fault you inject into the system.	Terminating an EC2 instance
Target	The resource(s) on which the action runs.	EC2 instances identified by tag `Service=api`
Stop Condition	A criterion—such as a CloudWatch alarm—that halts and rolls back the experiment when met.	CPU utilization > 80% for 5 minutes

Stop conditions are optional but strongly recommended. They prevent runaway experiments and ensure safety.

Prerequisites

AWS CLI v2 installed and configured
IAM role with permissions:
- fis:CreateExperimentTemplate
- fis:StartExperiment
- ec2:TerminateInstances
- cloudwatch:DescribeAlarms
EC2 instances tagged with FaultInject=true

Step 1: Define the Action

We’ll terminate EC2 instances tagged for the experiment. Use the following snippet in your experiment template:

"actions": {
  "terminateInstances": {
    "actionId": "aws:ec2:terminate-instances",
    "description": "Terminate targeted EC2 instances",
    "parameters": {
      "instances": ["${TargetInstanceIDs}"]
    }
  }
}

Step 2: Specify the Target

Identify EC2 instances by tag. You can also use resource IDs or ARNs.

"targets": {
  "TargetInstanceIDs": {
    "resourceType": "aws:ec2:instance",
    "resourceTags": {
      "FaultInject": "true"
    }
  }
}

Step 3: Add a Stop Condition

Define a CloudWatch alarm that stops the experiment when CPU usage exceeds 80% for 5 minutes:

"stopConditions": [
  {
    "source": "aws:cloudwatch:alarm",
    "value": "arn:aws:cloudwatch:us-east-1:123456789012:alarm:HighCPUAlarm"
  }
]

Ensure your CloudWatch alarm ARN is correct. A misconfigured stop condition may not trigger, leaving experiments running longer than intended.

Step 4: Launch the Experiment

Combine the components into a single template and create it with the AWS CLI:

aws fis create-experiment-template \
  --tags Name=TerminateEC2Test \
  --description "Terminate EC2 instances with guardrails" \
  --role-arn arn:aws:iam::123456789012:role/AWSFISRole \
  --actions file://actions.json \
  --targets file://targets.json \
  --stop-conditions file://stop-conditions.json

Once the template is created, start the experiment:

aws fis start-experiment \
  --experiment-template-id et-0123456789abcdef0

Cleanup

After testing, delete your experiment template to avoid orphaned resources:

aws fis delete-experiment-template \
  --experiment-template-id et-0123456789abcdef0

Introduction

Building a Basic FIS experiment

Introduction to Real life Application

Chaos Engineering on Compute - EC2

Chaos Engineering on Database - Aurora

Chaos Engineering on Serverless - Fargate

Chaos Engineering on Kubernetes- EKS

Chaos Engineering on Availability Zone

Conclusion

Chaos Engineering Fundamentals

Create FIS Experiment

Table of Contents

Core Components

Prerequisites

Step 1: Define the Action

Step 2: Specify the Target

Step 3: Add a Stop Condition

Step 4: Launch the Experiment

Cleanup

Links and References

Watch Video

​Table of Contents

​Core Components

​Prerequisites

​Step 1: Define the Action

​Step 2: Specify the Target

​Step 3: Add a Stop Condition

​Step 4: Launch the Experiment

​Cleanup

​Links and References

Watch Video

Table of Contents

Core Components

Prerequisites

Step 1: Define the Action

Step 2: Specify the Target

Step 3: Add a Stop Condition

Step 4: Launch the Experiment

Cleanup

Links and References