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SCOM: Creating a PowerShell script monitor with Silect MPAuthor

Sometimes it’s necessary to create a monitor to monitor something which is not included in the standard management packs. Unfortunately it’s not possible in SCOM  to use PowerShell to crerate a script monitor in the scom console. Although it’s not a good idea to start authoring in the operations console it sometimes can be a quick and easy way to create a monitor.

Recently Silect Sofftware released a free version of MPAuthor to create your management packs. I’m using this to create my script monitors to collect and monitor the data which I use in my monitoring my home series: http://scug.be/dieter/2014/02/19/monitor-your-home-with-scom/

Download the tool here: http://www.silect.com/mp-author

Below is an example of how I monitor the target temperature set on my Nest Thermostat.

So open the tool and create a new management pack => Create New Script Monitor…

SNAG-0243

Name the script (if you have the script somewhere as a PS1 file it will load the script body automatically.

SNAG-0246

This is the script I’m using:

[xml]

param([int]$maxtarget)
[void][system.reflection.Assembly]::LoadFrom(“C:\Program Files (x86)\MySQL\MySQL Connector Net 6.8.3\Assemblies\v2.0\MySQL.Data.dll”)

#Create a variable to hold the connection:

$myconnection = New-Object MySql.Data.MySqlClient.MySqlConnection

#Set the connection string:

$myconnection.ConnectionString = "Fill in the connection string here"

#Call the Connection object’s Open() method:

$myconnection.Open()

$API = New-Object -ComObject "MOM.ScriptAPI"
$PropertyBag = $API.CreatePropertyBag()

#uncomment this to print connection properties to the console
#echo $myconnection

#The dataset must be created before it can be used in the script:
$dataSet = New-Object System.Data.DataSet

$command = $myconnection.CreateCommand()
$command.CommandText = "SELECT target FROM data ORDER BY timestamp DESC LIMIT 1";
$reader = $command.ExecuteReader()
#echo $reader
#The data reader will now contain the results from the database query.

#Processing the Contents of a Data Reader
#The contents of a data reader is processes row by row:

while ($reader.Read()) {
#And then field by field:
for ($i= 0; $i -lt $reader.FieldCount; $i++) {
$value = $reader.GetValue($i) -as [int]
}
}
#echo $value
$myconnection.Close()
#$value = $value -replace ",", "."

if($value -gt $maxtarget)
{
$PropertyBag.addValue("State","ERROR")
$PropertyBag.addvalue("Desription","Target temperature currently set to " + $value + ": is higher than the maximum target temp " + $maxtarget)
}
else
{
$PropertyBag.addValue("State","OK")
$PropertyBag.addvalue("Desription","Target temperature currently set to " + $value + ": is lower than the maximum target temp " + $maxtarget)
}

$PropertyBag

[/xml]

Note that you need to pass the parameters through to SCOM via the propertybags. I also am a fan of doing the logic in the script itself as shown above to avoid any logic in SCOM afterwards. It’s far more easy to do the comparison in the PowerShell script. In this case I’m setting State to either ERROR or OK. This also avoids the format conflict of the output whether it’s a string or an integer.

I’m setting the maxtarget parameter to 19

SNAG-0245

Next you need to create the conditions for the monitor states:

SNAG-0247

As I’m only using a 2 state monitor I’m deleting the OverWarning state and only using UnderWarning (= Healthy state) and OverError (= Error state).

SNAG-0248

For the Healthy state I’m detecting the “State” property value as OK (note that I’m defining the Type as a String as the state is just plain text)

SNAG-0249

For the Error state I’m detecting the “State” property value as ERROR

SNAG-0250

Now we need to target the monitor. In my case it’s the watcher node target I’ve created earlier on.

 

SNAG-0251

Naming and enabling the rule

SNAG-0252

Set the schedule how many time to check the status of the max temp

SNAG-0253

Speciffy the alert that needs to be raised if any:

SNAG-0255

And create.

SNAG-0256

Now save the management pack and test it in your environment.

Enough talk, let’s build
Something together.