The extent to which a MOM 2005 implementation is self-maintaining depends largely on the volume of data flowing into and being removed from the operations database. The "Versions" section in Chapter 2 explains how data is groomed out of the operational database at configurable intervals. These intervals need to be coordinated with the DTS data transfer job that runs from the reporting server and copies (not deletes!) data from the operations database to the data warehouse database. In a nutshell, you want to be certain that data is copied to the data warehouse database more frequently than it is groomed (deleted) from the operations database. The default configuration is to copy data from the operations database to the data warehouse every day at 1:00 a.m. You can configure the grooming process in the Database Grooming section of the Global Settings node. The OnePoint database grooming will not occur if the daily DTS transfer has not completed successfully, so you are protected from losing data.
Figure 5-27. Configuring the default agent to management server communication port
Deleting data from the operations database happens differently for alert data than it does for performance or event data. The difference is that alerts must be in a resolved state before they can be deleted out of the database. After all, it wouldn’t be very helpful to delete an alert ...