This article serves to explain the process of a standard Aria Operations(formerly known as vRealize Operations) data collection, and how it arrives at a value for a data point.
The below mostly pertains to the VMware vSphere solution and may differ for other solutions.
Aria Operations(formerly known as vRealize Operations) out of the box, is configured to collect data every 5 minutes from the source.
For vCenter performance counters, the collector wakes up every 5 minutes and gets the last 15 samples of 20 seconds interval from the source.
15 Data Points X 20 Seconds = 300 Seconds ( 5 minute collection cycle)
Once the 15 samples are in, we go ahead and average them out to come up with the value which is saved in the FSDB (File System Database) of Aria Operations(formerly known as vRealize Operations).
In parallel, operations such as threshold checking, computed metric calculation etc. take place.
You can further transform this data in views and super metrics by using functions such as Min, Max, Standard Deviation etc
All these functions run on the data saved in FSDB which is the 5 minute data point explained above.
These transformations are not ran on the 20 seconds samples.
The 20 seconds samples in fact are used to do calculations of the 5 minutes data points and are dropped as soon as that calculation is done. This reduces the storage requirement drastically.
Note: It is possible to change this default collection cycle from 5 minutes all the way down to 1 minute, however it is not recommended to do that unless you understand the overall impact on Compute and Storage for increased collection and processing.