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Probe health becomes flaky with 80 sensors



We have a setup where a probe monitors 20 machines, with 4 sensors on each:

  • SNMP CPU test - 10 seconds timeout (we found it to be better than 60 seconds timeout in another case).
  • SSH meminfo
  • SSH disk free
  • SSH custom script - a very light script on the server side

The probe's machine is Very strong: 16 cores, 16GB memory, Windows server 2012 - dedicated for this probe.

The 20 machines (with a total of 80 sensors on them) are not responding - since they are shut down - this is intentional. The 20 machines should go up only from time to time.

We get a very poor performance from the probe itself:

  • More than 80% interval delay SNMP.
  • We keep loosing connection to the probe - it becomes "disconnected" for tens of minutes at a time.
  • Relatively high thread count sometimes - more than 300.
  • All of the SSH sensors, a vast majority of the time, show no data (grey color).

All of this is co-located in our offices. We see more or less the same performance when we run the probe from within the cloud data-center where the sensors should be monitoring.

bug performance prtg sensor-instability snmp

Created on Apr 29, 2015 10:23:51 AM

1 Reply



Please use our SNMP Tester (https://www.paessler.com/tools/snmptester), run it on the PRTG Host (or host of the Remote Probe), and perform a "Scan available standard interfaces" and uptime test against the target device.

Which results do you get in the Tester? Does it take long as well? Is the PRTG server connection slow altogether? Could it be an issue with the switch connecting it to the network?

Created on May 4, 2015 11:57:58 AM by  Stephan Linke [Paessler Support]

Last change on May 4, 2015 12:08:54 PM by  Stephan Linke [Paessler Support]

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