# Tutorial: Schedule a recurring experiment
With AWS Fault Injection Service (AWS FIS), you can perform fault injection experiments on your AWS workloads. These experiments run on templates that contain one or more actions to run on specified targets. When you also use Amazon EventBridge, you can schedule your experiments as a one-time task or recurring tasks.
Use this tutorial to create an EventBridge schedule that runs an AWS FIS experiment template every 5 minutes.
**Topics**
+ [
## Prerequisites
](#recurring-experiment-prerequisites)
+ [
## Step 1: Create an IAM role and policy
](#recurring-experiment-step1)
+ [
## Step 2: Create an Amazon EventBridge Scheduler
](#recurring-experiment-step2)
+ [
## Step 3: Verify your experiment
](#recurring-experiment-step3)
+ [
## Step 4: Clean up
](#recurring-experiment-step4)
## Prerequisites
Before beginning this tutorial, must have an AWS FIS experiment template that you want to run on a schedule. If you already have a working experiment template, make note of the template ID and AWS Region. Otherwise, you can create a template by following the instructions in [Tutorial: Test instance stop and start using AWS FIS](fis-tutorial-stop-instances.md), and then return to this tutorial.
## Step 1: Create an IAM role and policy
**To create an IAM role and policy**
1. Open the IAM console at [https://console.aws.amazon.com/iam/](https://console.aws.amazon.com/iam/).
1. In the left navigation pane, choose **Roles**, and then **Create Role**.
1. Choose **Custom trust policy**, and then insert the following snippet to allow Amazon EventBridge Scheduler to assume the role on your behalf.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "scheduler.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
```
------
Choose **Next**.
1. Under **Add permissions**, choose **Create policy**.
1. Choose **JSON**, and then insert the following policy. Replace the *your-experiment-template-id* value with the template ID of your experiment from the Prerequisites steps.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "fis:StartExperiment",
"Resource": [
"arn:aws:fis:*:*:experiment-template/your-experiment-template-id",
"arn:aws:fis:*:*:experiment/*"
]
}
]
}
```
------
You can restrict the scheduler to only run AWS FIS experiment templates that have a specific tag value. For example, the following policy grants the `StartExperiment` permission for all AWS FIS experiments, but restricts the scheduler to only run experiment templates that are tagged `Purpose=Schedule`.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "fis:StartExperiment",
"Resource": "arn:aws:fis:*:*:experiment/*"
},
{
"Effect": "Allow",
"Action": "fis:StartExperiment",
"Resource": "arn:aws:fis:*:*:experiment-template/*",
"Condition": {
"StringEquals": {
"aws:ResourceTag/Purpose": "Schedule"
}
}
}
]
}
```
------
Choose **Next: Tags**.
1. Choose **Next: Review**.
1. Under **Review policy**, name your policy `FIS_RecurringExperiment`, and then choose **Create policy**.
1. Under **Add permissions**, add the new `FIS_RecurringExperiment` policy to your role, and then choose **Next**.
1. Under **Name, review, and create**, name the role `FIS_RecurringExperiment_role`, and then choose **Create role**.
## Step 2: Create an Amazon EventBridge Scheduler
**To create an Amazon EventBridge Scheduler**
1. Open the Amazon EventBridge console at [https://console.aws.amazon.com/events/](https://console.aws.amazon.com/events/).
1. In the left navigation pane, choose **Schedules**.
1. Verify that you are in the same AWS Region as your AWS FIS experiment template.
1. Choose **Create schedule**, and fill in the following:
+ Under **Schedule name**, insert `FIS_recurring_experiment_tutorial`.
+ Under **Schedule pattern**, select **Recurring schedule**.
+ Under **Schedule type**, select **Rate-based schedule**.
+ Under **Rate expression**, choose **5 minutes**.
+ Under **Flexible time window**, select **Off**.
+ (Optional) Under **Timeframe**, select your time zone.
+ Choose **Next**.
1. Under **Select target**, choose **All APIs**, and then search for **AWS FIS**.
1. Choose **AWS FIS**, and then select **StartExperiment**.
1. Under **Input**, insert the following JSON payload. Replace the *your-experiment-template-id* value with the template ID of your experiment. The `ClientToken` is a unique identifier for the scheduler. In this tutorial, we are using a context keyword allowed by Amazon EventBridge Scheduler. For more information, see [Adding context attributes](https://docs.aws.amazon.com/scheduler/latest/UserGuide/managing-schedule-context-attributes.html) in the *Amazon EventBridge User Guide*.
```
{
"ClientToken": "",
"ExperimentTemplateId": "your-experiment-template-id"
}
```
Choose **Next**.
1. (Optional) Under **Settings**, you can set the **Retry policy**, **Dead-letter queue (DLQ)**, and **Encryption** settings. Alternatively, you can keep the default values.
1. Under **Permissions**, select **Use existing role**, and then search for `FIS_RecurringExperiment_role`.
1. Choose **Next**.
1. Under **Review and create schedule**, review your scheduler details, and then choose **Create schedule**.
## Step 3: Verify your experiment
**To verify that your AWS FIS experiment ran on schedule**
1. Open the AWS FIS console at [https://console.aws.amazon.com/fis/](https://console.aws.amazon.com/fis/).
1. In the left navigation pane, choose **Experiments**.
1. Five minutes after you create your schedule, you should see your experiment running.
## Step 4: Clean up
**To disable your Amazon EventBridge Scheduler**
1. Open the Amazon EventBridge console at [https://console.aws.amazon.com/events/](https://console.aws.amazon.com/events/).
1. In the left navigation pane, choose **Schedules**.
1. Select your newly created scheduler, and then choose **Disable**.