How to collect EC2 metrics

Amazon's CloudWatch service is used to collect EC2 metrics and events. Users can access these metrics through the CloudWatch web console, AWS command line tool, or a program or third-party monitoring service that connects to the CloudWatch API. The service gathers metrics via hypervisor instead of reporting from instances themselves, so it doesn't collect all resource metrics such as memory usage statistics. To fill this gap, custom metrics can be forwarded to CloudWatch and monitored using the same methods outlined above. Additionally, comprehensive monitoring services that integrate with EC2 and the rest of a user's stack can provide deeper visibility into instances and infrastructure components.