Tandem Capacity Model (TCM) Manual

To make sure a method is reasonable, save a model for each apportionment method and follow
the steps in “Updating History With Several Examples” (page 82).
Check the workload apportionment model of your application by comparing your results from all
samples by reviewing the Capacity History file. In general, an Apportionment Weights table can
be viewed as reasonable if CPU and disk demands per transaction are relatively constant across
many performance samples with varying transaction mixes and throughput levels. The requirement
for a variety of transaction mixes is crucial. If mixes do not vary, any apportionment method will
appear to be reasonable but might not be.
For more information, see “Checking an Apportionment Method” (page 82).
Checking Category 98
When working with MeasTCM, check the contents of the process category that contains all the
remaining processes not aggregated to other categories (_OTHER). If this category contains a high
number of unexpected processes, either consider:
• Editing the control file to create a new category to accommodate these processes
• Modifying the existing categories to include this activity
For more information, see “Using the Process Category Audit Report” (page 62).
Collecting Measure Samples
For MeasTCM to extract and summarize Measure data, the Measure sample data must meet several
requirements. For a complete list of these requirements, see “Collecting Measure Samples”
(page 30).
Converting TCM Models From Earlier TCM Product Versions
If you open a file created with an older product version of TCM, an alert message notifies you of
the product version mismatch. TCM automatically converts the file and then renames the older file
by replacing the first letter of the file name with an underscore (_).
For example, the original file bank.HST is renamed _ank.HST, and the converted file is now named
bank.HST. A Microsoft Excel dialog box appears when the conversion is done.
Creating Additional Workload Apportionment Models
Creating additional WA models involves loading additional performance data samples into your
WA model for apportioning. This approach allows you to apportion a variety of data samples to
determine the reasonableness of the apportionment method. Creating additional models allows
you to update the Capacity History database with many samples, to select appropriate samples
for modeling, and to create baseline data for input to the Performance model. You must have at
least 10 samples to use the throughput trending feature available in the Performance model.
The following procedure results in one or more saved, apportioned WA models with an updated
history.
To create additional Workload Apportionment models:
1. To download performance data samples to the PC, follow the download procedure you
normally use in Windows. All CSV files for the same application or set of applications should
be kept in the same folder, and all CSV files must have the extension .CSV. TCM detects any
truncated data and issues an error message.
2. If you are already in the WA model, load a CSV file into the current model. (See “Loading a
CSV Sample Into a WA Model” (page 240).)
If you are at the “TCM Initial Menu” (page 66):
a. Select Work With Existing Model. The Open WA Model dialog box displays the available
WA models.
b. Select an existing apportioned model to use as a template for all the new WA models
that you want to create.
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