Tandem Capacity Model (TCM) Manual

Capacity History Screens
The Capacity History screens–Database, TrendCharts, and MixCharts–are used to archive and
organize apportioned performance data for a particular application or set of applications. The
information in the Capacity History database is valuable in assisting the capacity planner in such
crucial activities as:
• Checking the reasonableness of an apportionment method for a custom WA model
• Choosing a representative performance sample as a baseline for the TCM Performance model
• Projecting trends based on historical data in the Performance model
• Performing database queries against historical data
• Creating historical charts
The Capacity History screens display summary performance information for each transaction in a
given application (or set of applications) across multiple performance samples. The database can
also store data for several different apportionment methods, so the capacity planner can easily
examine the effect of different apportionment methods on several historical samples.
Capacity planners can search the database by selecting Search from the History menu. Figure 43
(page 123) shows part of a sample Capacity History database screen.
NOTE: A given Capacity History screen is restricted to only one application (the name defined
in the MeasTCM control file on the host), but it can contain the results of more than one
apportionment method if needed.
Figure 43 Capacity History Database Screen
Significant Rows
1. Application—Not directly modifiable
Application is the user-specified name of the application or set of applications that is being
modeled. It is also the application name that appears on the Category Demand report of the
WA model. This name is specified when MeasTCM is executed on the NonStop host system.
(See “Customizing Your Process Category Control File” (page 33).) All the historical data on
the Capacity History screen pertains to this application. (An error message appears if you
select Update History from the History menu for a sample with a different application name.)
2. Search Criteria—Modifiable by the user
Search Criteria is a collection of fields in which you can enter values before selecting Search
History or Delete History from the History menu. You can specify several database criteria to
Capacity History Screens 123