Cutting outliers from graphs

[mamal]

I have a bunch of graphs that have issues with outliers from bad data input, like this:



I need to cut the outliers (the spike) from the graph. Displayed is a case where the spike is only about 6x the normal activity, but when the spike is 500x the normal activity, the meaningful data cant be seen if viewing a timeframe which includes the spike; In a case like this the spike is the only thing visible if it is high enough.

I'm assuming I can go into the zabbix database and delete the spike datapoints, or update them to set them to zero or some more reasonable value. Which tables am I looking to do this in? I notice there are a handful of tables that have to do with graphs, don't want to screw anything up. Any pointers?

The data issue that caused the spike is a separate issue, just looking for a process to remove outliers.

[kewan]

If you want to mess with the actual data in your database, I think you should look at the trends and trends_uint tables, depending on the datatype.
On the other hand, as a quick workaround, you could modify the graph itself and set the Y axis max value to a sensible one, so any spike would just shoot out of the graph without changing its scale. The graph would still report wrong max and mean values, but it would be meaningful at least from a graphical point of view.

cheers,

Stefano