Tandem Capacity Model (TCM) Manual

as type F if its CPU and disk consumption do not increase as throughput increases, such as
during asynchronous data communications polling activity or the running of Measure.
3. Apportionment—Not directly modifiable
Apportionment indicates the apportionment method used by the WA screen. The apportionment
method name is the name of the apportionment table file (without the .AWA extension) that
was used to generate the apportionment formulas when Workload Apportionment was selected
from the Update menu.
Significant Columns
4. Txn Name—Modifiable by the TCM administrator
Txn Name is the name of the transaction as defined on the NonStop host system using
MeasTCM. In MeasTCM, you can specify the transaction names for each transaction in the
application or applications being modeled. You can specify up to 40 transactions.
If no transaction names are specified in MeasTCM, TCM assumes that each server category
(type S) represents a transaction and uses the corresponding server category names as
transaction names.
5. First Unlabeled Column—Not directly modifiable
The first unlabeled column shows the type of a transaction: X for OLTP transactions, B for batch
transactions, or Q for query transactions.
6. Second Unlabeled Column—Not directly modifiable
The second unlabeled column indicates Aud if the transaction is audited but is left blank
otherwise. A transaction is considered audited if it has a nonzero entry in the TMF process
category in the Apportionment Weights table.
7. # Tasks—Modifiable by the TCM administrator
# Tasks is the number of tasks on the NonStop host system during the time period of the sample
window. This number applies to batch transactions only.
8. # Txns—Not directly modifiable
# Txns is the number of transactions on the NonStop host system during the time period of the
sample window. This number is computed according to the user-specified Transaction Count
table, which specifies how to calculate the number of transactions from the number of messages
received, sent or both by the process categories, or is input through the Transaction Count
file. For more information, see “Transaction Count Table” (page 118) and the “Transaction
Count Table Versus Transaction Count File” (page 120).
9. Write Seconds per Transaction—Not modifiable
Write Seconds per Transaction are the apportioned number of disk write seconds consumed
per transaction. The Average Txn column contains the (weighted) average of disk seconds for
each transaction. Disk seconds are the number of seconds spent doing physical disk access,
including seeks. Seek seconds are apportioned by MeasTCM on the NonStop host system
according to the relative number of reads and writes performed.
The WA model distinguishes between disk seconds consumed by the various processes of a
transaction, such as the server, requester, disk, TMF, line handler, and other processes.
Disk read and write seconds are apportioned to transactions according to the userspecified
Apportionment Weights table.
Workload Summary Screen
The Workload Summary screen summarizes the results of Workload Apportionment and displays
the apportioned CPU, disk read, and disk write seconds for each transaction. The data on this
Workload Summary Screen 113