What is rrdtool and why its needed
RRDtool is the OpenSource application which is used for data logging and creation graphics for time series data.
Practically, it can do two things:
1. Collect smartly some kind of integer data into db file.
For example, you want to track count unique visitors and amount visited pages on your website per day, week, month. Basically, you can specify any row of data, it can even be several sources like associative array. I’m going to show how it works in different post soon.
2. Draw cool graphics.
Basing on created db file you can specify how to draw cool graphics. Graphics tool is already installed with rrdtool. So, one thing what you need is just write small script and define colors for reflection data on graph. I’m sure small practical example should help a lot better to understand how user friendly this tool is.