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IIS Hybrid Sensors: Performance Counters and WMI

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When there is an issue with the Performance Counters, the sensor will automatically fallback to WMI. After 24 hours it will test Perf Counters and if they are working correctly, will switch back to Performance Counters. My question is if there is anyway to lower this 24 hours period (i.e. retest for Performance Counter more often). If so will this affect the probe's performance?

fallback hybrid-sensor performance-counters wmi-iis

Created on Aug 18, 2016 2:28:47 PM



3 Replies

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There's no switch or registry hack to configure this differently. The only thing that might work would be setting it manually to "WMI only" or "PerfCounters only" in the device's "Settings" tab, section "Windows Compatibility Options", perform a scan and switch back to "Performance Counters and fallback to WMI".

Kind regards.

Created on Aug 19, 2016 2:19:52 PM by Erhard Mikulik [Paessler Support]



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Thank you Erhard! The problem is that switching manually to "PerfCounters only" is not really practical for a big infrastructure when you have a lot of devices. And if the infrastructure is small, then you probably don't need to do it anyways as the WMI should be low. Since you said there is no switch or registry hack, I guess this is hardcoded with the sensor.

Do you have any statistics how the probe performance is affected when switching from PerfCounters to WMI ? If there is a significant load footprint, would you consider adding an option for lower/custom period in the future releases?

Created on Aug 22, 2016 8:22:45 AM



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You're welcome. I'm afraid we don't have statistics about the difference on load between WMI and using "Performance Counters only". Keep in mind that also not all WMI sensors have this "hybrid" approach (using primarily Performance counter and WMI as fallback). It is more important to keep an eye on staying below 200 WMI sensors per probe for overall stability, since this whole DCOM/RPC/WMI "black hole" is not very fast in general and causes more load (on PRTG side and the queried host) as SNMP sensors for example. For large installations we even recommend to not use more than 120 WMI sensors per probe.

Kind regards.

Created on Aug 23, 2016 9:04:04 AM by Erhard Mikulik [Paessler Support]

Last change on Aug 23, 2016 9:04:17 AM by Erhard Mikulik [Paessler Support]




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