How to manage collected data

If you intend to configure historical data collection, you must make provisions for handling the collected data. Without such provision, on distributed computers the history data files grow unchecked, using up valuable disk space. On z/OS® systems, the data sets allocated to the persistent data store are emptied and overwritten.

On distributed systems, if warehousing of the data is configured, the files are automatically pruned after the data is inserted into the Tivoli Data Warehouse by the Warehouse Proxy agent. On z/OS systems, the persistent data store data sets are not pruned after data is inserted into the Tivoli Data Warehouse by the Warehouse Proxy agent. A record is written in the persistent data store to indicate where to begin exporting data to the Warehouse Proxy agent the next time, and the exported data is kept in the persistent data store until it is overwritten or deleted by other means.

Tivoli Management Services provides automatic maintenance for the data sets in the persistent data store. When a data set becomes full, the persistent data store selects an empty data set to make active. When the data set is active, the persistent data store checks to see whether any data sets are empty. If not, the persistent data store begins maintenance on the oldest data set. However, before it begins processing, it checks to see whether one or more of the following functions have been configured:
  • BACKUP makes an exact copy of the data set being maintained.
  • EXPORT writes the data to a flat file in an internal format that can be used by external programs to post-process the data. This function is also used for recovery when the persistent data store detects potential problems with the data.
  • EXTRACT writes the data to a flat file in human-readable form suitable for loading into other database management systems (DBMS).
If no function has been specified, the data is deleted from the data set.

You specify which maintenance options are implemented when you configure the persistent data store. Persistent data store V1 (PDS V1) provides more information about how the persistent data store operates and how maintenance is performed.