The AppDynamics standalone Machine Agent is a Java program that runs on a host machine and collects hardware and infrastructure metrics, such as CPU, memory, disk, and network usage. The Machine Agent can also perform additional functions, such as:
Acting as a forwarder for analytics events: The Machine Agent can be configured to forward business transaction, log, browser, mobile, and synthetic events from the application agents to the AppDynamics Events Service, which is a distributed, scalable data store for analytics data. The Machine Agent can also forward custom events from the SDK or API to the Events Service. This allows you to use the AppDynamics Analytics features, such as dashboards, queries, funnels, and metrics, to analyze the performance and behavior of your applications and users12.
Starting an HTTP listener for custom metrics: The Machine Agent can be configured to start an HTTP listener that can receive custom metrics from external sources, such as scripts, tools, or other applications. The Machine Agent can then report these custom metrics to the AppDynamics Controller, where youcan view them in the Metric Browser or use them in health rules, policies, or dashboards. This allows you to monitor any aspect of your system that is not covered by the default Machine Agent metrics34.
The other statements are false because:
B. The Machine Agent cannot send SNMP alerts. The Machine Agent can only receive SNMP traps from external sources and report them as events to the AppDynamics Controller. The AppDynamics Controller can send SNMP alerts to external systems based on health rule violations or events, but this is not a function of the Machine Agent5 .
C. The Machine Agent cannot communicate with multiple AppDynamics Controllers. The Machine Agent can only communicate with one Controller at a time, which is specified in the controller-info.xml file in the agent configuration directory. If you want to monitor the same host machine with multiple Controllers, you need to install multiple Machine Agents on the same machine, each with a different Controller configuration and port number .
D. The Machine Agent cannot restart itself if it goes down. The Machine Agent does not have a built-in mechanism to automatically restart itself in case of a failure or a crash. You need to use an external tool or script to monitor the Machine Agent process and restart it if necessary. Alternatively, you can use the AppDynamics Agent Installer to deploy the Machine Agent as a service, which can be configured to restart automatically on failure .
References: Analytics Agent, Analytics Data, HTTP Listener, Custom Metrics, SNMP Trap Alerting Integration, [SNMP Integration], [Machine Agent Configuration Properties], [Install the Machine Agent], [Agent Installer], [Start and Stop the Machine Agent]
