Decision 8: Whether to collect historical data and how to manage it

Historical data collection is an optional feature that is enabled through the Tivoli Enterprise Portal or the OMEGAMON enhanced 3270 user interface. If you enable historical data collection, monitoring agents are instructed to take data samples at a specified interval and store it. The collected data can be displayed in workspaces in the Tivoli Enterprise Portal or the enhanced 3270 interface, warehoused for in-depth analyses and long-term data reporting, and exported to third-party tools for reporting and analysis.

Important: The content in this section was created for and applies to the original persistent data store, referred to as PDS V1. A new PDS version (referred to as PDS V2) now exists. PDS V1 will eventually be deprecated.

Historical data collection can be configured through either Tivoli Enterprise Portal or the enhanced 3270 interface. In the Tivoli Enterprise Portal, you configure and start historical data collection through the History Collection Configuration window of the Tivoli Enterprise Portal.

In the enhanced 3270 user interface, you configure historical data collection using the OMEGAMON History Configuration workspace. In both instances, you specify the attribute groups for which you want data to be collected, the interval for data collection, the location where you want the collected data to be stored (at the monitoring server or at the agent). In the Tivoli Enterprise Portal, you can also specify whether you want the data to be migrated to the Tivoli® Data Warehouse. Note that you cannot configure data warehousing through the enhanced 3270UI, nor can you configure summarization and pruning. Only a subset of attributes can be configured and displayed in the enhanced 3270UI.

On z/OS® systems, historical data is stored in data sets maintained by the persistent data store. If you enable historical data collection during configuration, space is allocated for the data sets. Persistent data store maintenance options should also be configured.

Important: The Tivoli Enterprise Portal displays only 24 hours of data from the persistent data store data sets (short-term history). Data older than 24 hours is taken from the Tivoli Data Warehouse (long-term history). So to display more than 24 hours of data in the portal, you must configure data warehousing. The enhanced 3270UI can display as much data as is stored in the persistent data store (near-term history). However, the enhanced 3270UI cannot display data from the Tivoli Data Warehouse and you cannot configure the Warehouse Proxy and Summarization Pruning agents from the enhanced 3270UI.

Historical data collection consumes CPU and storage, so it is important to plan data collection carefully. Consider the following planning decisions before you begin to configure historical data collection and storage: