History Collection

StealthCollect rapidly collects and aggregates performance data for historical analysis. It lets you configure the collection and aggregation in accordance with your monitoring and analysis needs. Configure an existing historical collection, using the following four displayed tabs:

Caution: Historical collection customization should be performed only by advanced users. Misconfiguration may damage the quality of your historical analysis.

Oracle Dimensions

Select/clear the dimension checkboxes as per your desired collection set.

Collection Settings tab

Specify in this tab's SQL collection settings:

• The value for the collected dimension setting has a greatest impact on top level dimension comprehensiveness (and therefore accuracy). The item combinations setting more directly affects second and third level dimension drilldowns.
  The overall tradeoff is between the number (depth) of collected occurrences and impact on space.

• If the Remove literals in SQL is checked, the agent replaces constants in SQLs with bind variables, so that statements that differ only in constants are treated as the same. Activating this option is useful where bind variables are not used.

• The Ignore statements checkbox lets you ignore statements active for less than a designated threshold period.

Time Pyramid tab

All layers must be specified with a positive value range and every layer should be retained for a minimum of twice the next layer resolution (for example one day must be kept for at least two weeks; one minute must be kept for at least 30 minutes).

The purpose of the time pyramid tab is to give an optimized storage and performance and rapid access to the data of interest. The logic of this model is based on the premise that the closer the data is to the present, the more granular (that is, measured in finer time units) you want it to be. Conversely, the further it is from the present, the less refined the desired time unit of measurement, illustrated as follows:

Placing the cursor focus on a Resolution line lets you change the storage duration in the sliding window box below and view the impact on the respective middleware and repository space layers. You can also view the impact on the overall Estimated storage periods.

Middleware Disk Space

Short term historical data is stored in files (in the middleware host). The estimated required entire space is Allocated (designated) at the time of installation. The data directory (located on the middleware host) contains the short-term history log files. This space is allocated during installation and therefore the directory should have sufficient free space to hold the indicated amount of required data. The Free space is the available unused space in the specified directory. If the free space is less than the allocated, it appears in red and you must either select a less demanding history model (or manually customize) or find a sufficient data directory location.

Performance Repository Space

(For long-term installations with Performance Repository.) These tablespaces constitute the long-term historical data. Estimated size for the repository schema is the size of the tables or indexes (respectively data or index tablespaces) required to host the entire defined historical data. As the Performance repository can house historical data for several years, you are not required to allocate the entire free space at installation.

The Allocated space determines the already allocated schema size, expanding in accordance with repository size growth. If the Free space is less than that needed to allow the schema to expand to that of the total Estimated size, it appears in orange, indicating that more space should be added to the tablespaces as historical data is added and the schema expands. (You may proceed without adjustments, though you will have to add additional space in the future.)

Space Allocation Override

Use this feature to manually override the system-determined Allocated middleware space requirements (to a maximum of 20 GB).

You can also specify an alternative Data directory.

To select the data directory location

1. Either accept the provided default, manually enter a data directory, or use the browse () option. Until sufficient space is found for the data directory, you are prevented from continuing with the installation.

2. Click Next.