Roll-up Process

Before the raw data is purged, the data is summarized, or “rolled-up”, at predefined intervals. Roll-up data is the term given to the data that has been summarized. Before any raw data is purged, the minimum, maximum, and average values are calculated and can be preserved in several ways.

Hourly data is the term given to data that is summarized, or rolled-up, every hour. The raw data for each hour is processed to create a summary record for that hour. For example, if raw data is logged every five minutes, a total of twelve raw records are available in one hour. When this data is rolled-up after one hour, the twelve raw records are processed in order to find the minimum, maximum, and average values during that hour. One summary record is generated for the twelve raw records. The hourly data is first computed on the agent machine, and is then brought over to the server machine where it is added to the database.

This method is the way raw data is rolled-up into hourly data at the end of each hour.

The daily, weekly, and monthly values are calculated in a similar manner. The maximum, minimum, and average values are also calculated for each period.