The AppDynamics agent for Node.js instruments a single Node.js process. Instrumentation enables the agent to discover, map and track metrics for business transactions, application services, and backends in your Node.js application. Typically there is a one-to-one correspondence between a process and a Node.js application but sometimes an application consists of multiple processes.
This agent communicates with a Java proxy dameon that handles the communication between the Node.js agent and the AppDynamics Controller. The proxy reports the performance metrics to the Controller, where the data is stored, baselined, and analyzed. You can access this performance data interactively using the Browser UI or programmatically using the AppDynamics REST API.
The proxy component is automatically started when you start the Node.js app agent.