InterMapper probes are software plug-ins that perform several functions:
- Retrieve data from the device being tested
- Compare the data to certain thresholds
- Set the device icon's state to up/down/warning/alarm/critical
- Format the contents of the device's Status Window.
You can create new probes or modify existing InterMapper probes to test equipment that's not tested by the built-in set of probes.
A good probe to use as a basis for development is the Interface Status probe. Download a copy from http://download.dartware.com/contrib/probes/com.dartware.snmp.demo.txt.zip.
There is an "interactive Probe Builder" web page at http://intermapper.com/probebuilder.aspx This allows you to create a simple probe easily.
For detailed information about creating probes, read InterMapper Developer Guide's reference section on Creating Probes.
Creating and Editing Probe Files
Probe files are simply text files. For simplicity, their filenames should end in ".txt". Probe files are saved in the InterMapper Settings/Probes folder. The easiest way to add a new probe to InterMapper is to import it (File->Import->Probe...)
You can edit probe files in your favorite text editor, even while the InterMapper server is running. After making changes to a probe file, you need to inform InterMapper that it has been updated. To do this:
- re-import it (the updated information will overwrite the earlier file)
- open the Set Probe... window and click the "Reload probes" icon at the lower right, or
- use the keyboard shortcut: Ctl-Shift-R in an editable map window (Cmd-Shift-R on a Mac).
In all cases, a confirmation window will appear to show that the probe was updated. If errors are detected, review the diagnostic messages in the Event Log window.
Parts of a Probe File
All probe files contain several sections. You can follow along by looking at the Interface Status probe or at the Probe Builder page (described below). Read the Developer Guide for the full details.
The sections of an InterMapper SNMP probe include:
- Introductory comment (generally enclosed in <!-- ... -->). This holds basic information about the probe, the author, revision history, etc. It is a comment, and does not affect the operation of the probe.
- <header> section gives the probe's human-readable probe name, the type (SNMP, TCP script, command line, etc.) and other parameters. It's easiest to duplicate an existing probe (like the Interface Status probe) and then modify the fields.
- <snmp-device-properties> section has infrequently-used flags. You can generally ignore this.
- <description> section gives a prose description of the probe as it will be viewed by the customer in the Set Probe... window. It uses the "InterMapper Markup Language" (IMML) to control the formatting.
- <parameters> section specifies the user-enterable parameters (entered in the Set Probe... window) to be used as thresholds, etc.
- <snmp-device-variables> section lists the OIDs that should be retrieved, as well as formatting information.
- <snmp-device-thresholds> section lists the threshold tests. These are the way InterMapper decides whether to mark the device as Up, Down, in warning, alarm, or critical.
- <snmp-device-display> section formats the information displayed at the bottom of the device's Status Window.
Interactive Probe Builder
Check out the "Interactive Probe Builder" web page that lets you experiment with entering SNMP OIDs and seeing the result immediately. This web page is a quick tool for seeing how changes to the parameters change the probe file. It's at http://intermapper.com/probebuilder.aspx