Over View:
OverTime is an application that combines the power and convenience of HP OpenView's data collection facilities and user interface with the graphical trending database facilities of Tobi Oetiker's RRDTool.

From a menu item within OpenView, OverTime takes a user selected device from the HP OpenView's map and
1) Decides what statistical information can be collected from the device to depict utilisation levels
2) Gathers these details directly from the device.
3) Configures HP OpenView to collect the information from the device.
4) Configures RRDTool databases to store the collected statistics.
5) Updates an HTML page so that the device's statistics can be viewed.

When the user selects the device on the HTML page via a browser, OverTime
1) Updates the RRDTool database from the information collected by HP OpenView.
2) Generates the appropriate graphic images for the statistics gathered for this device.
3) Generates an HTML page for the web server to display. (The same display can also be generated from the command line so that it may be relocated to different server for later display.)

In addition to the above HP OpenView menu item, 2 other menu items allow you to firstly stop collecting the data and secondly, show you what devices are currently being monitored by OverTime.

OverTime provides routines that, when run regularly
1) update all the RRDTool databases from the HP OpenView collected information and 2) prevents the HP OpenView collected information from growing until all available disk space is consumed.

RRDTool databases are fixed size, not growing due to their Round Robin technology. As new information is added to the database it is placed into a fixed size table. This table is then consolidated into another table covering a longer period, but with less granularity. This table in turn is consolidated into a third and finally into a fourth table. The oldest information in each table is replaced by the newest. The tables typically cover from 30 hours with a 5-minute spacing to over a year on a daily spacing.