Thursday, January 20, 2011

Graphing the interSeptor

After a considerable amount of mucking around, I persuaded various things to work together, and I now have Cacti making nice web-accessible graphs for me. My next project is to get a small "widget" display for OOAB that shows Current/Max/Min/Av values for temperature and RH.

If anyone ever needs them, the Jacarta interSeptor SNMP OIDs you need to read the Temp and Humidity are:
. = current temperature
. = current RH 
The values need to be multiplied by 0.1 to get a real temperature, as it stores the value as an integer with .1 of a degree increments.

Basically, the steps are to:
  1. Get a dyndns account or similar and make your router use it (if your machine/router/ has a dynamic IP address)  
  2. Use the port forward/firewall function of your router to forward any SNMP requests (port 161) to your interSeptor's internal IP address
  3. Install Cacti
  4. Use the SNMP OIDs to create graphs. 
  5. Because cacti uses dynamic references to its graphs, you're going to need to publish the graphs somewhere using the built in FTP function, or publish them to another web-accessible directory on the server running cacti. 
Relative Humidity
(these are still a work in progress)