NGINX Agent

The NGINX Web Server Agent monitors NGINX Webservers. Depending on the platform you use — Classic Agent or OneAgent, its architecture and functionality may differ. Find the detailed information below.

See Configure NGINX Agent to learn how to configure the Agent.

Architecture

Classic Agent

The Agent for Web Servers consists of two parts:

• The Web Server Module (slave) is the module that is loaded by the web server. It gathers the information that is used for analysis on the AppMon Server.
• The Web Server Agent (master) is a separate process that collects data of all worker processes (slaves). It is responsible for handling communication with the Collector, retrieving configuration data etc. See Web Server Agent configuration to learn how to configure this master agent.

Communication

The Web Server Modules communicate with the master Agent through these channels:

• A shared memory segment propagates configuration data, received from the Collector by the master Agent, to the worker processes and to hold other information that must be shared across all worker processes. The shared memory segment is backed by a file in <DT_HOME>/agent/conf on all platforms where the worker processes and the Agent process must have read/write access.
• The Web Server Modules (slaves) send collected data to the master Agent via a stateless UDP connection. The master Agent collects the data, transforms it, and forwards it to the Collector (standalone or Server-embedded).

OneAgent

The Agent for Web Servers consists only of a Web Server Module that is loaded by the web server. ollects data of all worker processes (slaves). It gathers the information that is used for analysis on the AppMon Server. The OneAgent is responsible for handling communication with the Collector. Find more information about OneAgent here.

To use OneAgent you need to install Classic Agents first, and then roll them out to the OneAgent.

Sensors

Sensor	Classic Agent	OneAgent
Webserver sensor
NGINX modules
User Experience sensor

FAQ

How do I find out which modules are instrumented?

Check the Agent log file in the AppMon Client:

1. Open the Agents Overview dashlet.
2. Right-click the required Agent and select Show Agent Log File.
3. In the System Information dashlet, select the required log file.