Rubella is a library to generate heatmaps to monitor visualize measured values easier. Like the load of multiple CPU cores over time.
Therefore every CPU core gets its own JSON array over the measured time. So the array gets it's own row in the headmap. The more the color itensity the higher is the load. (The values are in percent. So they must be beween 0 and 100.)
During the time you can see, if an unusual behavior occurs, because the image shows a different load distribution.
see also: http://dtrace.org/blogs/brendan/2011/12/18/visualizing-device-utilization/
Coming soon.