Monitoring Instances with Status Checks

With instance status monitoring you can quickly determine whether Amazon EC2 has detected any problems that may prevent your instances from running applications. Amazon EC2 performs automated checks on every running Amazon EC2 instance to identify hardware and software issues. You can view the results of these status checks to identify specific and detectable problems. This data augments the information that Amazon EC2 already provides about the intended state of each instance (pending, running, stopping, etc.) as well as the utilization metrics that Amazon CloudWatch monitors (CPU utilization, network traffic, and disk activity).

Status checks are performed every five minutes and each returns a pass or a fail status. If all checks pass, the overall status of the instance is OK. If one or more checks fail, the overall status is impaired. Status checks are built into Amazon EC2, so they cannot be disabled or deleted. You can, however create or delete alarms that are triggered based on the result of the status checks. For example, you can create an alarm to warn you if status checks fail on a specific instance. For more information, see Creating and Editing Status Check Alarms.

There are two types of status checks: system status checks and instance status checks.

System status checks monitor the AWS systems required to use your instance to ensure they are working properly. These checks detect problems with your instance that require AWS involvement to repair. When a system status check fails, you can choose to wait for AWS to fix the issue or you can resolve it yourself (for example, by stopping and restarting or terminating and replacing an instance). Examples of problems that cause system status checks to fail include:

Instance status checks monitor the software and network configuration of your individual instance. These checks detect problems that require your involvement to repair. When an instance status check fails, typically you will need to address the problem yourself (for example by rebooting the instance or by making modifications in your operating system). Examples of problems that may cause instance status checks to fail include:

ec2-report-instance-status [instance_id ...] [--status ...] [--reason] ..]