Today we use zenoss to store all the info from our machines. It stores about 3 or 4 years of data which helps us to evaluate trends or forecasts.
Zenoss also use a template mechanism to create DCI (and associate a correct polling interval). For instance, for each interface, we have in/out speed / packets /Errors, you can imagine how much it can be with 48 ports switches (or worst). Zenoss, just resample the data automatically, so you have a hour view, then daily, weekly and yearly. Of course we don't have a seconds resolution when we browse data 2 years old, but it is far enough to see trends.
I'm waiting for the snmp table implementation to prepare templates for switches, computers, printers, sensors (I'll share all the template), but storage optimization will be required to limit the impact.
Is it easy to select all the DCI values with date filter and re-compute them ? (ie : take x values, compute average and replace the values by only one )
We could be something like :
-take the last week values, and compute average per hour
-take the last year and compute average per days (or half day)