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Using WMI Process Monitor not accuratly showing Working Set



We are monitoring a java.exe process that appears to show 4300 MBytes in PRTG however the resource monitor (Windows 2012R2) shows a a drastically different number 12000000kb in fact which is 12000 MBytes not 4300. I am trying to correlate where that data in PRTG is being confused. I am trusting the windows resource monitor is the correct representation... this server has 24GB of memory and java is using 14gb of that right now. So the working set numbers seems completely off.

Unless there is an explanation based on how the data is calculated and represented in the charts. The java.exe can be spawned by the web application so there is not a consistent (1) java process at a time meaning it is possible for multiple java process to be running at once.

I know the sensor is looking for java.exe and even notes the instance count so i feel like that is part of the puzzle.

java memory process-monitor

Created on Aug 25, 2016 4:09:10 PM

4 Replies



So I have an update. I believe this is due to the limitation of the WMI Process Monitor sensor as stated here https://www.paessler.com/manuals/prtg/wmi_process_sensor

Note: This sensor type cannot show values above 4 GB for 64-bit processes if you run the PRTG probe with this sensor on a 64-bit Windows system. The WoW64 (Windows 32-bit on Windows 64-bit) emulation layer for 32-bit applications like PRTG limits monitoring values from 64-bit systems or processes to 4 GB and caps off greater values. To avoid this issue that is caused by Windows and to correctly monitor 64-bit processes, please add this sensor to a probe that runs on a 32-bit Windows system.

The question now is I apparently installed the 32 bit version of the PRTG on the 64bit system (i thought the install auto-negotiated this but non the less both the probe and server exe are listed as 32bit).

Would updating the PRTG installation (which only affects the server.exe) be worth while? If so how would I go updating in order to run the 64 bit server.exe instead while on the same system?

Created on Aug 25, 2016 7:32:06 PM




For the correct monitoring of 64-bit processes you have to run the PRTG Probe on a 32-bit machine... until Microsoft fixes that bug in the WoW64 layer.

The only solution we can recommend at the moment is to use a remote probe running on a 32bit Windows for these sensors.

Created on Aug 26, 2016 11:37:22 AM by  [email protected]



This might be a dumb question but why not have a 64 bit PRTG probe.exe?

Created on Aug 26, 2016 5:24:00 PM



We should be able to "workaround" this by creating a 64-bit probe software, but I've received feedback that this will not happen anytime soon as it would be extremely difficult to implement/convert and not many PRTG users asking for a 64-bit probe.

Created on Aug 29, 2016 1:26:55 PM by  [email protected]

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.