In this example, as part of a benchmark study, an
installation wants to prepare TPNS scripts to represent TSO
user activity. In particular, they wish to identify patterns
of think time and short, medium, and long TSO response events
to specify the TPNS scripts.
To identify the TSO activity patterns, the TSOTSU File was
analyzed. Four features were specified on the Workload
Characterization screen:
AVGTHINK - Average think time. This value is computed by
dividing the total think time (TSUTHKTM) by the
number of think time events (TSUTHCNT).
SREVPCT - The ratio of short response events to total
response events for the user during the CA TSO/MON
PM measurement interval. This value is calculated
by dividing the short response event count
(TSUSRESC) by the total response event count
(TSUTRESC).
MREVPCT - The ratio of medium response events to total
response events for the user during the CA TSO/MON
PM measurement interval. This value is calculated
using the TSUMRESC and TSUTRESC values.
LREVPCT - The ratio of long response events to total
response events for the user during the CA TSO/MON
PM measurement interval. This value is calculated
using the TSULRESC and TSUTRESC values.
You may be interested in the reason we used ratios rather
than counts to characterize the response event. Although we
could have calculated the arrival rate using the total
response event values, we could also have calculated the
arrival rate based on the average think time. Therefore, you
need only the ratio of the response event sizes rather than
response event counts, since you can use the average think
time to calculate the arrival rate. As we discussed in
Section 11.2.4, such rated features offer significantly fewer
problems in the control of outliers.
We selected five data elements as reporting variables:
TSUTGETS - The number of terminal TGETS issued
TSUTPUTS - The number of terminal TPUTS issued
TSUTCBTM - The TCB CPU time consumed by the commands
TSUSRBTM - The SRB CPU time consumed by the commands
TSUSWPSZ - The number of 1K blocks swapped for the user
Sample statistics, cluster centroids, and cluster assignments
for the total population are shown in Figures 11-30, 11-31,
and 11-32.
Figure 11-30 provides the sample statistics for the TSO data.
The maximum and minimum values for the ratios of short,
medium, and long commands are all 0 and 1. The 0 values
correspond to intervals when none of a user's response events
were of a specified duration. Conversely, the 1 values
correspond to intervals during which all of a user's response
events were of a specified duration.
Since all of the ratios were bounded by 0 and 1, outliers
were not a consideration. The minimal differences between
the sample and trimmed statistics demonstrate this fact.
However, examining the statistics for average think time
reveals some unexpected values. At first, the maximum value
(14,627 seconds) of the average think time appears to be
invalid. However, these long think times correspond to
sessions where the terminal was simply left logged on for
several hours without any activity. Therefore, the outliers
represent only inactive terminals. Because of this, the
representation of the outliers is of little or no concern for
this study.
The centroids of the 15 clusters that were developed are
shown in Figure 11-31, TSO Cluster Centroids Report.
Consider the characteristics shown for cluster 6. Cluster 6
represents approximately 21% of all of the TSO user
measurement interval records. The users represented by this
cluster have an average think time of 21.2 seconds and
experience short and medium response events in a ratio of 9
to 1. These characteristics are the typical input
requirements for system drivers like TPNS.
The final report for the TSO study, shown in Figure 11-32, is
the Cluster Assignment Report. In a benchmark study, you
would use this report to verify that the percent of the
resources that are consumed in the benchmark by the synthetic
workloads correspond to the distributions for the actual
system.
DESCRIPTIVE STATISTICS NUMBER OF OBSERVATIONS: 2000 ----------SAMPLE---------- ------TRIMMED 95.00%------ FEATURE MIN MAX AVERAGE STD DEV CV AVERAGE STD DEV CV -------- --------- --------- --------- --------- ---- --------- --------- ---- AVGTHINK 0.87 14627 107.463 555.687 5.2 42.0253 63.6419 1.5 SREVPCT 0 1 0.38403 0.388045 1.0 0.351269 0.370578 1.0 MREVPCT 0 1 0.358206 0.375055 1.0 0.324072 0.353648 1.1 LREVPCT 0 1 0.257764 0.403596 1.6 0.218288 0.375076 1.7
Figure 11-30. TSO Descriptive Statistics Report
CLUSTER CENTROIDS CLUSTER AVGTHINK SREVPCT MREVPCT LREVPCT RADIUS NO ASSIGN PCT ------- -------- -------- -------- -------- ------ --------- --- 1 19.7 0.0 0.0 1.0 1.50 339 17 2 25.0 0.1 0.9 0.0 1.50 347 17 3 127.9 0.5 0.5 0.0 2.00 33 2 4 147.8 0.0 1.0 0.0 1.50 49 2 5 20.0 0.5 0.5 0.0 1.50 395 20 6 21.2 0.9 0.1 0.0 1.00 411 21 7 19.6 0.5 0.1 0.4 1.50 55 3 8 233.1 0.0 0.0 1.0 3.00 28 1 9 427.0 0.0 1.0 0.0 2.50 18 1 10 20.8 0.1 0.4 0.5 2.00 85 4 11 540.5 0.0 1.0 0.0 2.00 81 4 12 267.1 1.0 0.0 0.0 3.00 34 2 13 296.9 0.0 1.0 0.0 2.00 21 1 14 103.6 1.0 0.0 0.0 1.50 61 3 15 122.0 0.0 0.0 1.0 2.00 43 2
Figure 11-31. TSO Cluster Centroids Report
CLUSTER ASSIGNMENT -- TOTAL POPULATION TOTAL OBSERVATIONS : 15104 OBS WITHIN RADIUS : 14568 MARGINAL ASSIGNMENTS: 536 3.5% CLUS WITHIN MARGIN TSUTGETS TSUTPUTS TSUTCBTM TSUSRBTM TSUSWPSZ ---- ------ ------ ---------- ---------- ---------- ---------- ---------- 1 2652 0 42742 179645 1:30:01 0:06:54 2534180 17.56% 22.42% 24.99% 27.99% 19.76% 22.84% 2 2715 0 27731 133719 0:54:28 0:06:07 1844684 17.98% 14.54% 18.60% 16.94% 17.52% 16.62% 3 247 0 1327 5877 0:02:38 0:00:20 110092 1.64% 0.70% 0.82% 0.82% 0.95% 0.99% 4 365 4 1188 9135 0:02:24 0:00:16 122952 2.44% 0.62% 1.27% 0.75% 0.77% 1.11% 5 2888 0 45130 162621 1:11:16 0:08:11 2440348 19.12% 23.67% 22.62% 22.16% 23.48% 21.99% 6 3114 0 53320 125302 0:41:40 0:07:25 2508048 20.62% 27.96% 17.43% 12.96% 21.28% 22.60% 7 367 3 5450 26948 0:15:30 0:01:30 315648 2.45% 2.86% 3.75% 4.82% 4.30% 2.84% 8 179 16 578 3790 0:01:55 0:00:13 75240 1.29% 0.30% 0.53% 0.59% 0.61% 0.68% 9 98 4 203 1176 0:00:26 0:00:03 20740 0.68% 0.11% 0.16% 0.14% 0.14% 0.19% . . 15 293 0 1269 8928 0:05:42 0:00:31 166184 1.94% 0.67% 1.24% 1.77% 1.49% 1.50% **TOTALS** 190681 718918 5:21:38 0:34:53 11097664
Figure 11-32. TSO Cluster Assignment Report
|
Copyright © 2014 CA.
All rights reserved.
|
|