To create a custom metric:

1. Go to the Configuration tab. Under Alerts and metrics, select Custom metrics:

   

2. Click the Create custom metric button:

   

The first page of a simple, three-step wizard is displayed. The steps are:

Step 1. Define metric - includes sections for defining the metric, and entering and testing the T-SQL query on which the metric is based.

Step 2. Add an alert - optionally base an alert on the metric by completing sections similar to those displayed on the Alert settings page (Configuration > Alert settings).

Step 3. Create - creates the custom metric and alert.