You use the Machine Agent to collect basic hardware metrics. The Machine Agent is a Java program that has an extensible architecture enabling you to supplement the basic metrics reported in the AppDynamics Controller UI with your own custom metrics. The Machine Agent is also the delivery vehicle for AppDynamics Server Visibility, which provides an expanded set of hardware metrics and additional monitoring capability. See License Entitlements and Restrictions for a complete list of licenses for Server Visibility and the Machine Agent.
Functionality provided by the Machine Agent includes:
Reporting basic hardware metrics from the server's OS, for example, %CPU and memory utilization, disk and network I/O
Reporting metrics passed to the Controller by extensions
The Machine Agent collects infrastructure metrics from multiple extensions and forwards them to the Controller. You can also use these metrics to find correlations between infrastructure issues on one or more servers and application-performance issues reported by the App Agents.