I was contacted by a client last week regarding a monitoring server they have deployed. One of the applications they have gathering data from this server is Cacti. Anyhow they were able to login to Cacti but the graphs were not displaying. After logging into the server, which is running CentOS Linux, I saw the error clearly in the Litespeed logs. Below I describe the error in more detail as well as how to resolve this problem if you run into it.
How do I create Cacti Graph Templates? How do I display multiple data sources on one Cacti graph? What do all the Cacti options mean? What is a CDEF? I created a Cacti Graph but all of my data sources are displaying NAN, how do I troubleshoot that?
Cacti is a powerful RRDTool based graphing system typically used for graphing hardware and software data for historical reference. When I initially configured a Cacti Graph Template I found some of the options confusing but as you will see below they all make sense and typically the name explains each items function in a fairly easy way. Please post a comment if you have any further questions that are not answered or if I have made any answers feel free to use the contact form and point them out to me as I am trying to learn the best way to use Cacti just like everyone else. I repeat the same terms many times in this document simply for the fact to try and explain in detail what things mean. I did not want to start switching names with acronyms and vice verse to add confusion and to try and make this a very easy document to understand.
Creating multiple cacti graphs using the same script is really easy. It took me a minute to realize it but if your script input values then you can just click the “Create Graph” drop down and create multiple of any graph you have configured. See the two images below that show how to do this visually.