Sensor of the Week: Passive Application Performance Sensor

 Originally published on August 27, 2014 by Florian Staffort
Last updated on March 03, 2022 • 7 minute read

Important note: The Passive Application Performance sensor is deprecated as of PRTG version 16.1.23. Please see the following article for more details: The PRTG Sensor Cleanup


In this week's blog article we present to you a very powerful sensor, you might yet not have been using. It's time to change that! Find out how the Passive Application Performance sensor has the potential to add real value to the way you monitor the performance of your servers and web applications.

Usually you either need access to the server or service you want to monitor, which can increase the time and effort you need to setup your network monitoring. The Passive Application Performance Sensor uses a completely different approach: It utilizes PRTG's built-in packet sniffer to look at all TCP packets going into a server and check the reply packets as well. By measuring the lifetime of a TCP connection, the sensor can determine the performance of the monitored service or server.


After a few minutes the sensor will begin to show you:

  • The number of currently active connections on all monitored applications,
  • The total number of packets dropped by PRTG because of system overload, and
  • The total number of packets observed on the selected network card.

In addition you can see four channels for each application that offer a deeper insight into the monitored server/service. The measured values can be used to indicate the development of the application's performance over a period of time which helps to determine, for example, if it is getting slower or if its performance is being steady.

If your internal infrastructure uses external services, for example, cloud services like Google Apps or Amazon EC2, or you need to monitor your own services without causing extra strain on them, PRTG's Passive Application Performance sensor is the way to go.

For more detailed information on the Passive Application Performance sensor please have a look at the PRTG manual and the blog article on its introduction to PRTG.


All Sensors of The Week

You have missed other articles of our "Sensors of the Week" blog series? Just take a look at the last 10 sensors:

Subscribe to our RSS feed to always stay up to date on new articles!