Tip of the Month: Creating Property-Driven Thresholds

This tip was courtesy of Chet Luther one of our services team.

Normally when you create a threshold, you have to choose the upper and/or lower limits. Sometimes you want these limits to vary considerably for different devices. It can be a lot of work to create many copies of the same template just so you can define different threshold values. However, there is a better way to solve this problem!

For this example we’ll create a property-driven threshold for the standard FileSystem template. This will allow us to setup a single threshold on the FileSystem template in the /Server device class and use a custom property at the device or even device class level to control its behavior.

First Step: Create the custom property

1. Go to /Devices
2. Click on the menu and choose More -> Custom Schema
3. Add a property:
   • Label = Maximum file system utilization
   • Name = cThreshMaxFileSystem
   • Type = int
   • Default = 90
   • Visible = True

Second Step: Create the property-driven threshold

1. Go to /Devices/Server
2. Click on the Templates tab
3. Click into the FileSystem template
4. Delete the existing Free Space 90 Percent threshold
5. Add a new threshold named nearly full:
   • Select usedBlocks_usedBlocks from the data points
   • Set the max value to:
     (here.totalBlocks) * (here.cThreshMaxFileSystem / 100.0)

Now you can go to the custom properties/schema of any device class or device and set what the percentage at which your file system threshold will trigger just by overriding the cThreshMaxFileSystem property.