Question

A CloudOps engineer manages a fleet of EC2 instances running a stateless web application. Occasionally an instance fails its EC2 instance status check (system reachability is fine, but the OS-level check fails), requiring a reboot to recover. The team wants a fully automated, serverless solution that reboots the affected instance immediately without maintaining any custom code or servers. Which approach best meets these requirements?

Accepted Answer

Create an EventBridge rule matching the EC2 instance status check failed event and target a Systems Manager Automation runbook (AWS-RestartEC2Instance) to reboot the instance

Answer

Configure a CloudWatch alarm on the StatusCheckFailed_Instance metric with a recover action to move the instance to new hardware

Answer

Create a CloudWatch alarm on the StatusCheckFailed_Instance metric that triggers an SNS notification, then have an on-call engineer manually reboot the instance

Answer

Deploy a scheduled Lambda function that polls the DescribeInstanceStatus API every minute and reboots any instance reporting a failed status check