This article applies as of PRTG 22

The mini probe interface

Probes are the part of PRTG that run monitoring processes and deliver monitoring data back to the PRTG core server. The standard probes in PRTG are local probes and remote probes but you can create these “big” probes only on Windows systems. The Mini Probe API (Application Programming Interface) enables you to add probes to any device running on any operating system. This makes it possible to fulfill specific monitoring needs.

The following mini probes are available for free and ready to use:

• Python Mini Probe (open source), see How can I monitor Linux systems with a PRTG Mini Probe?
• JMX Mini Probe (open source), see How can I monitor Java applications via JMX with a PRTG Mini Probe?
• PRTG Mobile Probe for Android, see How can I monitor Android devices? Is there a mobile probe?

Agentless vs agent-based monitoring

The focus of PRTG is to agentlessly monitor systems. This means that you do not need to install any software on the particular target systems. "Big” probes connect to remote systems using, for example, SSH, WMI, or SNMP to retrieve data. This is the preferred monitoring method because this does not require any maintenance on your behalf.

However, there are situations where it can be a good idea to do it the other way around: You install a small piece of software on the remote system that connects to the PRTG core server to deliver monitoring results.

Agent-based monitoring options

PRTG offers two options for the agent-based monitoring approach:

• HTTP Push Data sensors:
  • A program, for example, a script, cron job, or service on the remote system sends one value per request to a sensor using HTTP or HTTPS (this function is referred to as a webhook). Currently, PRTG provides four sensor types for this purpose: HTTP IoT Push Data Advanced sensor, HTTP Push Count sensor, HTTP Push Data sensor, and HTTP Push Data Advanced sensor.
• The Mini Probe API uses the following monitoring approach:
  • It is a small application that runs on the remote system.
  • It connects to the PRTG core server using HTTPS.
  • It announces the sensor types that it can monitor.
  • It gets configuration from the server (that is, the monitored sensors).
  • It schedules and runs the sensors by itself.
  • It delivers the sensor results back to the PRTG core server.

After you have connected a mini probe to the PRTG core server, you can use it in the PRTG web interface like common “big” probes, that is, add sensors, review monitoring data, and perform other monitoring tasks. Mini probes just have a smaller set of sensors, depending on what types you implement.

The Mini Probe API is publicly available, so you can create your own probes and corresponding sensors for any application scenario. This enables you to gather monitoring data from systems that do not run the supported Windows versions. For more information, see the Mini Probe API.

However, you do not have to start from scratch. You can simply extend our open source code for sample mini probe usages and add your own sensor types. See below for a list of mini probe applications that you can download for free.

Mini probe: proof of concept

Currently, we offer three mini probe implementations. You can download them on GitHub, respectively here, and set them up as described in the linked articles:

• Python Mini Probe (open source): The Python Mini Probe runs monitoring processes on Debian-based systems (for example, Linux, Raspbian). For details, see How can I monitor Linux systems with a PRTG Mini Probe?
• JMX Mini Probe (open source): The JMX Mini Probe can run on any Java Virtual Machine (JVM) to monitor your Java applications. For details, see How can I monitor Java applications via JMX with a PRTG Mini Probe?
• PRTG Mobile Probe for Android: The PRTG Mobile Probe for Android monitors your network from the mobile point of view. For details, see How can I monitor Android devices? Is there a mobile probe?

If you implement your own mini probe and want to share your work with other PRTG users, feel free to publish it in our Knowledge Base or contact us directly.

Note: Articles about mini probes are provided for your information only. All steps described in the respective mini probe articles have been thoroughly tested. However, we can neither offer deep technical support for customizing the proofs of concept nor for writing your own mini probes.