Quick Tour for MPE/iX Systems
In this tutorial, you will learn the following:
How to start Forecast
How to load a collection file
How to preview and validate a collection file
How to graph the information
How to specify workloads, CPUs, and gowth rates to be included in graphs
Overview
The Quick Tour in this chapter introduces first-time users to the features and functions of Forecast
Capacity Planner. For users upgrading from earlier versions of the software, these tours provide a
quick and easy way to get acquainted with the changes in the current version.
Before beginning the tour, install Forecast Capacity Planner along with the appropriate sample
files on your personal computer.
Running Forecast Capacity Planner
Loading a Collection File
Forecast Capacity Planner creates a model of your system based on the data collection (*.col)
files transferred from the host system. See
"MPE/iX Host Data" for information on host data
collection and data transfer.
Your software includes a sample collection file (HP3000A1.col) for use with this tour.
To load the collection file:
On the File menu, click Load/Validate model. The Open dialog box will appear (Figure 5.1).
In the Files of type list, click Collections (*col).
Click once on the collection file, HP3000A1.col, to select the file.
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Figure 5.1 Open dialog box (showing *.col files)
Click Open to load the collection file.
Choosing a CPU Equivalent
In some instances, the CPU naming conventions on the host will differ from those on the PC.
When that happens, Forecast will generate the Choose CPU dialog.
Figure 5.2 Choose CPU dialog box
The Choose CPU dialog states which CPU type cannot be found by the Forecast application. In
the example shown in
Figure 5.2, the CPU in question is a 3000/957. To resolve the issue, select
the equivalent CPU name from the pull-down list (for example, 3000/957) and click OK.
Investigating Validation Messages
As the loading process runs, you will receive a list of warnings and informational messages in the
Validation Messages dialog (
Figure 5.3). These messages provide information about workload
groups that may violate one or more modeling algorithm assumptions. For information about
these assumptions, see
"Validation Failures".
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Figure 5.3 Validation Messages dialog box
Normally, you would investigate the causes of these messages and determine what, if any,
influence they have on your model. It may be necessary to repeat running the data collection
process to collect another sample from the host system. Information about evaluating workload
groups is provided in
"Identifying and Characterizing Workload Groups".
For this exercise, assume that the messages do not affect the validity of the model. Click OK to
continue.
Previewing the Unvalidated Baseline Model
When the loading procedure is complete, the Main Program window will display. The name of the
file will also appear at the top left corner of the Forecast window. The window contains the
unvalidated data loaded from the host system. (The model is not validated until it is saved in the
Model (*.mdl) format.) The Main Program window for an unvalidated model is divided into three
panes:
The file manager pane.
The global unvalidated centers pane.
The global unvalidated workloads pane.
The content of each pane is described following the example shown in
Figure 5.4.
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Figure 5.4 Main Program window panes (unvalidated model)
The file manager pane
The file manager pane is a representation of the unvalidated model in outline form.
To expand or collapse the outline, click the Plus (+) or Minus (-) icons (respectively) within the file manager pane.
To access detailed information, click the individual CPU, Disk, or Workload icons.
Clicking on Centers (or anything contained within) will cause the Workloads pane to be hidden. Clicking on Workloads (or anything contained within) will cause the Centers pane to be hidden. To re-display both panes, click on the file name (HP 3000 MPE/iX Tutorial A1).
To edit items on the file manager pane, double-click the associated icon.
The global unvalidated centers pane
The global unvalidated centers pane displays the results for each CPU and disk drive in the
model. To view detailed information about a single resource in the model, click the associated
icon in the file manager pane.
The global unvalidated workloads pane
The global unvalidated workloads pane displays the results for each workload group included
in the model. To view detailed information about a single workload group in the model, click the
associated icon in the file manager pane.
Validation Thresholds
Normally, you would review the data in the Main Program window to determine if the model is a
valid representation of the system’s baseline performance. For this exercise, assume that the
model is valid.
Acceptable validation thresholds for each system resource are listed in the following table.
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Resource
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Pane/Column
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Acceptable Validation Variance
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CPU utilization
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up to 15 percent
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Transaction/hour (throughput)
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Workloads/ Var: Tran/Hr
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up to 30 percent
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Response time
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Workloads/ Var: Resp. Time
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up to 30 percent
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Disk I/O/second
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Centers/ Var: IO/sec
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Variances for disk I/O/second and disk queue length are ignored because most real-world situations do not account for issues like database spreading.
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Disk queue length
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Centers/ Var: Avg. Queue Length
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Select the workload group to revise.
Press Enter.
In the Edit Workload screen, make your changes.
Press OK.
Validating the Baseline Model
Validate the baseline model you have created:
On the Forecast menu, click Validated Model.
In the forecast dialog box, click Yes to begin the validation process. Notice that the name of the document (top left corner of the window) changes from HP3000A1.col to HP3000A1.mdl.
On the File menu, click Save Model As....
In the Save As dialog box, click Save to save the model in the default location on your computer.
Graphing the Model
The validated model created in the previous steps provides an accurate snapshot of your host
system. The real power of Forecast Capacity Planner is its ability to predict future performance
based on user-supplied what-if scenarios designed to illustrate the forecasting and graphing
capabilities of the software.
The examples in this section are based on the following assumptions:
Standard system performance tuning (defragging and balancing disk drives, repacking the database, etc.) will not significantly reduce CPU utilization or dramatically improve online response time, or reduce batch job completion time.
Workload definitions on the host system are unchanged.
Memory size and the type of disk drives are unchanged.
One CPU with Zero Growth Rate
For this example, graph the model validated in the previous exercises and assume no change in
utilization occurs for 24 months.
To create the graph:
On the Forecast menu, click Forecast Options. The Forecast Options dialog box will appear, showing the Options tab.
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Figure 5.5 Forecast Options dialog box: Options tab
In the Forecast Options dialog box, change the number in the Periods box to 24.
In the Growth Type list box, select Linear.
Verify the Period type is Month.
In the Workloads list box, verify that only the All workloads check box is selected.
Select the Adjust Results check box.
In the Graph Type list box, verify that CPU Util is selected.
In the Growth Option list box, click Override.
In the CPUs list box, verify that only the 3000/957 check box is selected (clear all other check boxes in the CPUs list box).
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Figure 5.6 Forecast Options dialog box: Options tab with new settings
In the Forecast Options dialog box, click the Rates tab.
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Figure 5.7 Forecast Options dialog box: Rates tab
Verify that Tiered rate and Growth rate are both set to 0 (zero).
Click OK to close the Forecast Options dialog box and save your changes.
On the Options menu, deselect the Prompt for titles option if it has been selected.
On the Forecast menu, click Graph Forecast. The forecast graph displays.
Figure 5.8 Baseline graph for one CPU with zero growth rate
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NOTE If the graph labels are overlapped, adjust the Font and Size parameters in the Graph Options dialog box from the Options menu (see "Fonts Options" and "Sizes Options").
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The upper line (XL Threshold) in the example graph (
Figure 5.8) represents the CPU utilization
threshold of 85 percent. 85 percent is the default threshold limit for MPE/iX systems and is
generally considered the level at which response time and batch process completion rates
become unacceptable. For information on changing threshold limits, see
"Setting Thresholds".
The lower line (All workload groups) in the graph represents overall CPU utilization for all
workload groups identified in the model (3000/957). The modeled CPU utilization of 67.1 percent
is approximately 18 percent below the threshold limit of 85 percent.
Four CPUs with Zero Growth Rate
In this example, compare the baseline forecast for your original model with three larger CPUs.
To create the graph:
On the Forecast menu, click Forecast Options.
In the Forecast Options dialog box, select the following CPU check boxes in the CPUs list box:
3000/957 (CPU selected in original model)
3000/977
3000/992-100
3000/995-200
Click OK to close the Forecast Options dialog box and update your graph.
Figure 5.9 Baseline graph for four CPUs with zero growth rate
The upper line (XL Threshold) in the graph represents the 85 percent CPU utilization threshold for
MPE/iX. The other four lines represent the CPU utilization for each of the four CPUs, based on
the workload groups identified in the original, baseline model.
As expected, the larger CPUs show a lower utilization rate for the modeled workload groups. The
3000/995-200, for example, can handle the same workload groups with approximately 21 percent
CPU utilization, compared with 67.1 percent CPU utilization on the 3000/957.
Four CPUs with Five-Percent Growth Rate
Repeat the forecast with a five-percent growth rate for all four CPUs.
To create the graph:
On the Forecast menu, click Forecast Options.
In the Forecast Options dialog box, verify that the following CPU check boxes are selected in the CPUs list box:
3000/957
3000/977
3000/992-100
3000/995-200
Click the Rates tab in the Forecast Options dialog box.
Click in the Growth Rate text box and type 5.
Click OK to close the Forecast Options dialog box and update your graph.
Figure 5.10 Baseline graph for four CPUs with five-percent growth rate
This example graph represents the modeled utilization rate for the 3000/957 relative to the rates
for the larger CPUs at a growth rate of five percent over 24 months. Notice that the model does
not simply add five-percent utilization to the rate for each month. The five-percent growth rate is a
factor used to calculate the growth of each of the workload groups, subject to the modeled
capacity of the system.
For example, the plotted curve for the 3000/957 begins to flatten at the threshold limit of 85
percent. The amount of increase in CPU utilization is constrained by the model as the CPU
approaches 100 percent utilization.
Without remedial action, the 3000/957 will reach the threshold capacity in December 2000.
Remedial action might include replacing the 3000/957 with a larger CPU, or improving system
performance.
Utilization by Workload Group for One CPU
For the last example, graph your original model for the 3000/957 for each workload group,
assuming a five-percent growth rate.
To create the graph:
On the Forecast menu, click Graph Forecast to close the graph and return to the Main Program window.
Note the percent utilization for each workload group displayed in the global validated workloads pane.
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Figure 5.11 Main Program window: global validated workloads pane
The CPU utilization for each workload group should read:
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3.0
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4.5
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2.1
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5.8
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13.2
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19.1
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19.4
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On the Forecast menu, click Forecast Options.
In the Workloads list box, deselect the All Workloads check box. Select each of the seven workloads individually.
In the Forecast Options dialog box, deselect all of the CPUs except the 3000/957 in the CPUs list box.
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Figure 5.12 Forecast Options dialog box, Options tab
Click OK to close the Forecast Options dialog box and save your changes.
On the Forecast menu, click Graph Forecast. The forecast graph displays.
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Figure 5.8 Baseline graph for one CPU with zero growth rate
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