What alarms should be used for TempDB filling up? (4279021)

Databases - Data File Group Space Used alarm:   This alarm is raised when a disk group (or the actual disk) is in danger of filling.  Once the disk group fills completely, attempts to update anything in that database may fail.  This calculation is based on the sum of the current size of all the files in the disk group compared with the sum of the file size limits for all the files in the disk group.

Databases - Log File Space Used alarm:   This alarm is raised when a log is almost full and the log files cannot automatically grow enough to relieve the problem.  When the free space in a database’s log file falls below a certain percentage of the log file’s current total log size, the alarm is raised.  Once a log fills completely, all attempts to update anything in that database will fail.  This alarm takes into account the amount of free space currently within a fixed sized log file.

You can setup an alarm action by going to "Configure | Alarm Action" to create an action to send an email alert for when the the tempDB reaches a threshold.

When get an alert you can then drill down for additional TempDB details as shown in this example.