This article applies to PRTG Network Monitor 19 or later

I need additional information on how to set up an HTTP Transaction sensor, especially on how to find out the correct POSTDATA settings.

The HTTP Transaction sensor - tips and tricks

By using the HTTP Transaction sensor, you can monitor a sequence of URLs on a web server. This is useful, for example, to ensure that placing products into a shopping cart and then passing the checkout actually works.

A word of caution

It is important to understand that for some web applications it can be quite complicated if not impossible to create an HTTP Transaction sensor in PRTG Network Monitor.

The HTTP Transaction sensor requires your web application to use cookies for session management. If your web application uses hidden fields, URL parameters, POST fields, JavaScript (or other methods that require interaction with a real browser) to store session id(s), then you can not monitor it using the HTTP Transaction sensor.

Please understand that our support team can not take over the duty of creating and debugging the HTTP Transaction sensor settings for you and your website. However, the sensor is already in use on many different websites and can be considered reliable.

What you need

The HTTP Transaction sensor simulates the HTTP requests that are sent to a server by a user visiting a sequence of webpages (while preserving the cookies during all requests).

To simulate this you must hand over the URLs and their POSTDATA (for POST requests only) to the HTTP Transaction sensor. Now figuring out the URLs is pretty easy. You can simply copy the URLs from the URL edit field of your web browser. But getting your hands on the POSTDATA is more complicated.

Getting POSTDATA via developer tools

By using your web browser's developer tools, you can get the POSTDATA in a few mouse clicks. The developer tools help you to find out the URLs and the POSTDATA strings that are sent to a web server while visiting a sequence of URLs.

Opening developer tools in Chrome

  • Go to Options | More Tools | Developer tools or via the Windows shortcut Control+Shift+I.
  • Go to the Network tab.

Opening developer tools In Firefox

  • Go to Options | Web Developer | Network or via the Windows shortcut Control+Shift+E.

Note: In both Chrome and Firefox, you can also right-click an element and inspect it to open the developer tools.

  • In the browser window, use the mouse etc. to go through the URL sequence you want to record. While you access each page, the URL and - if you submit a POST request - the POSTDATA is stored in the list of the developer tools console.
  • Stop the recording when you reach the last web page of your URL sequence.
  • When you are done, you can use the URL list's context menu to copy or save URLs or POSTDATA.

Note: For more information on the developer tools options, see your browser's website.

Transferring the data to PRTG Network Monitor

  1. Open the PRTG web interface.
  2. Create a new HTTP Transaction sensor and copy the URLs (and for POST requests, the POSTDATA) using the information from the developer tools into the edit fields of PRTG Network Monitor.
  3. Check the other settings of the sensor and submit the page.

Now you should be able to monitor the sequence as desired.

IMPORTANT: Be aware that if the sequence you recorded was a shopping cart or any other transactional activity, PRTG will now cause the same purchase or transaction every few minutes if you do not take any measures against this!


Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.