Using WMI to discover Windows based systems

[amoss98]

Hello everyone,

I have been working on Discovery for a few months now and I am currently having an issue discovering Windows based systems. I have tried discovering a few different varieties that our organization uses (Windows 7, Windows 10, Server 2016, etc) and it seems that nothing is being done after the WMIRunner is sent out. What is throwing me off is that the discovery does not fail, rather it appears to complete without any issue. Looking at the Device tab of the Discovery Status page, I can see that the "current activity" is Classifying, however there is no other information except the source IP address. Out of curiosity, I hopped on one of our MID server hosts and attempted to use 'wmic' to reach a remote Windows machine and that appears to be working correctly from what I can tell.

Is there anything in particular I should be looking at? There's probably something relatively simple that I may be overlooking. Definitely a learning process for sure!

[chuckm · Accepted solution]

I had a similar issue a few months ago. Discovery was working fine, then all Windows discoveries stopped at the WMI: Classify. Just as you describe - nothing was being returned by the WMIRunner and Discovery didn't fail but shows "Discovery completed" in the Discovery log.

We had recently patched Java on our MID Servers to Oracle Java 8 release 231 (build 1.8.0_231-b11/8.0.2310.11). This version introduced Runetime.exe and ProcessBuilder argument restrictions that the MID server uses for running some PowerShell commands. ServiceNow has posted a work around for this by adding wrapper.java.additional.3=-Djdk.lang.Process.allowAmbiguousCommands=true to the wrapper-override.conf.

I provide more details in this community article:  Discovery PowerShell WMI Probes Fail After Upgrading the MID Server Oracle JRE to version 8 release ...

[amoss98]

chuckm,

I actually just stumbled across that by doing some searching.

After reading you article and the HI article that is mentioned here I discovered this issue with Oracle's JRE. I went ahead and installed OpenJDK as it is mentioned in the MID Server system requirements  (plus we are trying to move away from Oracle's Java distribution) and everything seems to be working as it should. Now I can continue on with my discovery journey! 😊

Thanks for the help!

[Runjay Patel]

Check out this video, it will clear all your doubts and help you to understand Discovery queries in details.

Link: https://www.youtube.com/watch?v=30JbWVsusyE&t=10s&ab_channel=ServiceNowHelpdesk

It help you to understand below points.

• Discovery Overview
• Discovery prerequisite
• Understanding Discovery Phases in details
• Discovery credentials and IP Affinity
• Mid Server Management with Cluster and Load Balancer
• Schedule jobs
• Set up discovery from scratch to end
• Live implementation with real world data.
• Troubleshooting on various aspects
• Many more other issue related to mid server, CIs
• Cloud discovery
• Service Mapping

Please mark reply as Helpful/Correct, if applicable. Thanks!!