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In this guide, we’ll verify the configuration of our Aurora PostgreSQL cluster and set up the IAM role required for AWS Fault Injection Simulator (FIS).

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1. Review Aurora PostgreSQL Cluster Configuration

Ensure your Aurora PostgreSQL cluster is deployed regionally with the following setup:
Instance RoleAvailability ZoneStatus
Writerus-east-1aAvailable
Readerus-east-1bAvailable

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2. Establish Baseline Metrics in CloudWatch

Before running an FIS experiment, capture steady-state performance metrics:
  1. Open the AWS Console and navigate to CloudWatch → X-Ray Trace Map.
  2. Select your target database (e.g., the adoption PostgreSQL cluster).
  3. Set the time range to the last 30 minutes.
You should observe metrics similar to these:
MetricTypical Value
Latency~2 ms
Request Rate~26 requests/min
FaultsNone
The image shows an AWS CloudWatch Trace Map interface displaying metrics for a database service, including latency, request rate, and fault rate over a 30-minute period.
Recording baseline metrics is essential for measuring the impact of your FIS experiments. Always capture steady-state data first.

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3. Create an IAM Role for FIS

AWS FIS needs permission to act on your RDS resources and write logs. Follow these steps:
  1. Navigate to IAM → Roles → Create role.
  2. Under Trusted entity, choose AWS service, then select FIS.
  3. For Use case, pick RDS.
  4. Name the role FISRDSRole.
  5. In the Trust policy editor, replace the JSON with: 
    {
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["sts:AssumeRole"],
      "Principal": {
        "Service": ["fis.amazonaws.com"]
      }
    }
  ]
}
  6. Attach the managed policy CloudWatchLogsFullAccess (or a least-privilege equivalent) to enable logging.
Your IAM role is now ready to be selected when you configure and run your FIS experiment.
The image shows an AWS Identity and Access Management (IAM) console screen, displaying details of a role named "KK-fis-rds-role" with attached permission policies.
Always follow the principle of least privilege. Grant only the permissions necessary for your FIS experiments to reduce security risks.

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References

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