I´m using rrd4j for on/off chart (value is only 0 or 1), but chart looks terrible, is not “binary” but some type of avarage function.
How to options rrd4j for better look of chart?
I think when you start looking back over previous days, you would still run into this problem with rrdj4. By design, it compresses and so averages old data.
You may need to consider another persistence DB (you can have more than one at the same time).