ID: 8539
Title: Made consolidation of values transparent to the user
Component: metrics
Level: 2
Class: Bug fix
Version: 1.4.0i1
When showing graphs of larger time ranges, the graphs are normally based on
aggregated values, which means multiple measured values are consolidated to
a single value.
For example, when a graph is based on the "max" aggregation function, like
nearly all graphs are by default, the values in the Average column are not
the real average values of the shown time, but the average values of the
max values in the step of the graph. The step of the graph is now shown on
the top right of the graph.
To clarify this: If you look at a 7 day graph, you have a step of 30 minutes.
If the service is being checked in a 1 minute interval, the graph is based on
the maximum of 30 single values of each 30 minutes step.
So your average values are the 7 day average of the 30 minute maximum values.
This is obviously not what most users would expect, but we would have to fetch
3 times more data per graph to get the real average and the real min values
for each graph. The graphs are already producing a lot of load and we try
to keep the impact low, so we decided to make the calculation transparent and
changable by the user.
If you have a max graph, the min and average columns are slightly grayed out
to visualize the situation. If you hover on the titles, you get a description
about it. Now you can click on the columns titles to change the aggregation
function the graph is based on.