A common problem faced when displaying graphs in a cycle of weeks or months, is that peak erosion, i.e. the height of peaks can not be read off the graph.
As an example, look at the following two views of the same data:
- Shows a peak of height 0.8 on a view scale of a few hours.
- Shows a peak of height 0.2 on a view scale of several days.
How is that possible?
When viewing a graph on a large time scale, there are not enough pixels on the screen to display all that data at once.
Hence, an aggregation function has to be applied before we view the data.
Circonus uses averages to aggregate the data to a sensible resolution.
This works well in most circumstances, but for judging the height of peaks, this is not a good fit.
What to do about it?
We offer alternative aggregation functions as overlay under: "SLA Monitoring" -> "Percentile Aggregation".
Added with the default options, this will show the minimum and the maximum of all values that have to be aggregated.
With this overlay, you are able to see the height of the peaks on large time scales.