Monday, May 03, 2010

WMI Web Site Discovery with System Center Operations Manager

Learning how to perform a discovery with WMI under SCOM/OpsMgr isn’t easy – documentation is appalling and there’s few examples on the net. Here’s my, eventually, successful attempt with some lessons learned along the way.

First off a quick description of the original problem – I want to discover multiple instances of web services running on servers.

After much, much time spent building a single server SCOM/OpsMgr development environment (just exactly what do people call this product anyway?) and figuring my way tentatively through SCOM and the SCOM Authoring Console I defined a class based on Microsoft.Windows.LocalApplication. If you ever have any issues with this stuff a good place to go is the Operations Manager Authoring discussion board – one of my questions and the helpful response from Elizabeth 1978 is here.


Then I created a discovery based upon a wmi query against the root\webadministration namespace to retrieve a list of sites. (Try it out in Powershell first: get-wmiobject –query “select * from site” –namespace root\webadministration.)



Now try to simulate this (learning to use the simulate tool as an experiment in itself – remember to load the MP into SCOM then click the arrow heads to attach to your development RMS so expressions can be resolved)… and it doesn’t work.




Strange. Then by trial and error I find that the asterisk doesn’t allow SCOM to pick up the data element for the name from the WMI query. Basically it seems to need you to identify each value you want returned in the WMI query to be sure you can map it in the Authoring Console mapper screen.

So this works:


You can check by running a simulation.


And to be doubly sure I imported the management pack into the SCOM environment with a monitor that targeted the class and checked when the ASP.NET Apps v4.0.30319 Requests/Sec counter was in excess of 10 requests/second.

As a web service I used a wcf service – just a simple hello world affair (in F# – why is there no template in visual studio??) and executed from a powershell console.

1..1000 | foreach-object {(new-object“http://localhost/service.svc”) }

1 comment:

JR said...

Hi, I'm new to SCOM and just came across your post - it seems very useful, but I was wondering where this "simulate tool" you mention can be found. I'm having quite a few problems with WMI discoveries and I'd really love to be able to test them out.