The number of rows per day generated by a monitoring agent collecting
historical data for an attribute group can be calculated with the following
formula:
( 60 / collection interval) * 24 * (# instances at each interval)
Where:
- 60 Represents the 60 minutes in an hour.
- collection interval The
data collection interval, in minutes. This value can be 1, 5, 15, 30, 60,
or 1440 (1 day).
- 24 Represents 24 hours in one day.
- # instances at each interval The
number of instances recorded at each interval.
The two variables in this formula are the collection interval
and the number of instances recorded at each interval.
- The collection interval is a configuration parameter specified in the
Historical Data Collection configuration dialog.
- The number of instances recorded at each interval depends on the nature
of the attribute group and the managed system being monitored. Some attribute
groups, such as NT_Memory, generate a single row of data per collection interval.
Most attribute groups, however, generate multiple rows of data, one row for
each monitoring instance (for example, one per CPU, one per disk, and so on).
Certain attribute groups can be instance-intense,
generating dozens or hundreds of rows of data per collection interval. Examples
of instance-intense attribute groups would be those reporting information
at the process level, thread level, disk level (for file servers), or network
connection level.
For attribute groups that return multiple rows, the number of
instance recorded at each interval is configuration dependent, and can be
different from one monitoring environment to another. The Warehouse load projections
spreadsheet requires the user to specify the number of instances recorded
at each interval. There are several approaches that you can use to come up
with this number.
- Using the portal client, build a table view for the monitoring agent and
define a query to obtain data from the desired attribute group. The number
of rows shown in the table view is the number of instances that would be recorded
at each interval. For details on how to define table views in the portal client,
refer to the IBM Tivoli Monitoring User's Guide.
- Issue a SOAP call to collect data for this attribute group from the monitoring
agent. The number of data rows returned by the SOAP call is the number of
instances that would be recorded at each interval. For details on how to issue
SOAP calls, refer to Appendix A “Tivoli Enterprise Monitoring Web services"
in the IBM Tivoli Monitoring Administrator's Guide.
- If you have a test environment, you can create a monitoring server to
use in historical data collection testing. Enable historical data collection
for the desired attribute group under this remote monitoring server, and configure
a representative agent to connect to this monitoring server. When the agent
uploads data to the Warehouse Proxy agent, you can query the WAREHOUSELOG
table to see how many rows were written by the agent for the attribute group.
To minimize the data volume (rows per day) generated by a monitoring
agent for an attribute group, consider the following two recommendations:
- Use the longest data collection interval (1, 5, 15, 30, 60 or 1440 minutes)
that will provide the desired level of information.
- Avoid or minimize data collection for instance-intense attribute groups,
which can generate a large number of rows per data collection interval.
Monitoring, Version 6.2